EXHIBIT 10.56
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                           CONVERTIBLE PROMISSORY NOTE
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$500,000.00                                                      May 26, 2000


      1.  Amount;  Maturity.  FOR  VALUE  RECEIVED,  the  undersigned,   GENETIC
VECTORS, INC., a Florida corporation (the "Maker"), promises to pay to JIM KELLY
(the "Holder"),  the principal sum of FIVE HUNDRED THOUSAND  DOLLARS  ($500,000)
which principal sum shall mature on the day that is one hundred and eighty (180)
days from the date hereof (the "Maturity  Date") and shall bear simple  interest
at the rate set forth herein.

      2.  Interest.  Interest  shall  accrue  as of the date of this Note at the
simple  interest rate of twelve percent (12%) per annum.  All accrued but unpaid
interest shall be due and payable on the Maturity Date.

      3.  Mode of Payment. All payments of principal and interest due under this
Note shall be made in legal tender of the United States of America and delivered
to the Holder at or, at the option of the  Holder,  in such other  manner and at
such other place as the Holder shall have designated to the Maker in writing.

      4.  Prepayment.

          (a) This Note may be voluntarily prepaid,  without penalty or premium,
in whole or in part,  at any time and from  time to time.  Any  prepayment  must
include all accrued interest on the principal being prepaid, through the date of
prepayment.

          (b)  Subject  to  Section 5 hereof,  this  Note  shall be  mandatorily
prepaid  in the event  that the  Maker  closes an  offering  of its  securities,
whether through one or more private placements or secondary public offerings, in


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which the Maker raises gross proceeds from such  transaction or  transactions of
at least  $5,000,000.  The Maker shall have fifteen (15) business days to make a
mandatory prepayment to the Holder of this Note pursuant to this Section 4(b).

      5.  The Holder hereof shall have the following  conversion rights:

          (a) Any  Holder of this Note shall have the right at any time prior to
the  payment in full of the  principal  balance of this Note to convert all (but
not  less  than  all)   amounts   due  under  this  Note  into  fully  paid  and
non-assessable  shares of the Maker's  common stock,  $0.001 par value per share
(the  "Common  Stock").  The number of shares of Common  Stock (the  "Conversion
Shares")  into which this Note may be converted  shall be determined by dividing
(a) the sum of all amounts due under this Note (including,  without  limitation,
all  principal  and  accrued  but  unpaid  interest)  up to  and  including  the
Conversion Date (as defined below) by (b) Three Dollars (US $3.00) per share (as
adjusted in accordance with Section 5(d) hereof) (the  "Conversion  Price").  No
fractional shares of Common Stock or scrip representing  fractional shares shall
be issued upon  conversion  of this Note.  Instead of any  fractional  shares of
Common Stock which would  otherwise be issuable upon conversion of the Note, the
Maker shall pay to the Holder a cash adjustment in respect of such fraction.

          (b) To  exercise  its  conversion  privilege,  the Holder of this Note
shall  surrender  the  original  Note  representing  the debt  obligation  being
converted to the Maker at its principal office, and shall give written notice to
the Maker at the office that the Holder  elects to convert  such Note.  The Note
surrendered  shall  be  accompanied  by  proper  notice  of  waiver  of the debt
obligation in the form required by the Maker.  The date when such written notice
is received by the Maker,  together with the original Note representing the debt
obligation  being  converted  and all other  instruments  required by the Maker,
shall be the "Conversion  Date." As promptly as practicable after the Conversion


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Date,  the Maker  shall  issue and  deliver  to and in the name of the  Holder a
certificate or certificates for the Conversion Shares.  Such conversion shall be
deemed to have been effective on the Conversion  Date and Holder shall be deemed
to have become the Holder of record of the Conversion Shares at such time.

          (c) From and after the date  hereof,  until thirty (30) days after the
effective date of a registration statement filed by the Maker in connection with
the registration of its securities with the Securities and Exchange  Commission,
including,  without limitation,  a Form SB-2 Registration Statement,  the Holder
shall have the right by  providing  written  notice to the Maker to exercise its
conversion  privilege.  In the event the Holder  does not make its  election  in
accordance  with the  provisions in this Section 5(c),  the Holder shall receive
the warrants as set forth in Section 5(f) hereof.  In the event the Holder makes
its election in accordance  with the provisions in this Section 5(c), the Holder
shall receive the warrants as set forth in Section 5(e) hereof.

          (d) In the event that the Maker shall (1) pay a stock  dividend in and
on shares of its Common Stock,  (2) subdivide its  outstanding  shares of Common
Stock into a greater  number of shares,  (3) combine its  outstanding  shares of
Common Stock into a smaller number of shares,  or (4) issue by  reclassification
of its  shares  of Common  Stock  any  shares  of its  capital  stock,  then the
Conversion Price in effect  immediately  prior thereto shall be adjusted so that
the Holder of this Note  surrendered for conversion after the record date fixing
shareholders  to be affected  by such event  shall be  entitled to receive  upon
conversion the number of such shares of Common Stock which the Holder would have
been  entitled to receive  after the  happening of such event had this Note been
converted immediately prior to such record date. Such adjustment, if applicable,
shall be made on the  effective  date of such event and shall also be  effective


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retroactively  as to the principal  amount of this Note  converted  between such
record date and the effective date of the event.

          (e) In  the  event  that  the  Holder  shall  elect  to  exercise  its
conversion  privilege as set forth in Section 5 hereof, the Holder shall receive
(1) a warrant  from the Maker that  entitles  such Holder to  purchase  from the
Maker one hundred sixty-six thousand six hundred sixty-five  (166,665) shares of
Common  Stock of the Maker at a purchase  price per share of Six  Dollars  (U.S.
$6.00) (as  adjusted in  accordance  with Section 5(d) hereof) and (2) a warrant
from the Maker that  entitles such Holder to purchase from the Maker one hundred
sixty-six  thousand six hundred  sixty-five  (166,665) shares of Common Stock of
the Maker at a purchase price per share of Seven Dollars and 10/100 (U.S. $7.10)
(as adjusted in accordance with Section 5(d) hereof).

          (f) In the  event  that the  Holder  does not  elect to  exercise  its
conversion  privilege as set forth in Section 5 hereof, the Holder shall receive
(1) a warrant  from the Maker that  entitles  such Holder to  purchase  from the
Maker one hundred  thousand  (100,000)  shares of Common Stock of the Maker at a
purchase price per share of Six Dollars and 60/100 (U.S.  $6.60) (as adjusted in
accordance  with  Section  5(d)  hereof)  and (2) a warrant  from the Maker that
entitles such Holder to purchase from the Maker one hundred  thousand  (100,000)
shares  of  Common  Stock of the  Maker at a  purchase  price per share of Eight
Dollars (U.S. $8.00) (as adjusted in accordance with Section 5(d) hereof).

      6.  Registration Rights

          (a) In  the  event  that  the  Holder  shall  elect  to  exercise  its
conversion  rights  pursuant to Section 5 hereof and the Maker  shall  receive a
written request, not earlier than one hundred twenty (120) days from the receipt
by the Maker of a minimum  amount of gross  proceeds equal to $5,000,000 in such
offering,  from such Holder that the Maker file a registration  statement  under


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the  Securities  Act of 1933,  as amended (the  "Securities  Act")  covering the
registration of the shares the Conversion  Shares,  then the Maker shall effect,
as expeditiously as reasonably  possible,  the registration under the Securities
Act of such Conversion  Shares that such Holder  requests to be registered.  The
Maker shall not be required to effect a  registration  pursuant to this  Section
6(a) after the Maker has effected one (1) registration  pursuant to this Section
6(a), and such registration has been declared or ordered effective.

          (b) The Maker  shall  notify  the Holder of the  Conversion  Shares in
writing  at least  thirty  (30) days  prior to the  filing  of any  registration
statement  under  the  Securities  Act for  purposes  of a  public  offering  of
securities of the Maker (including,  but not limited to, registration statements
relating to  secondary  offerings of  securities  of the Company and will afford
such Holder an opportunity to include in such registration statement all or part
the Conversion  Shares held by such Holder. In the event that the Holder desires
to include in any such registration  statement all or any part of the Conversion
Shares  held by it, the Holder  shall so notify the Maker in wirting  within ten
(10) days after the  above-described  notice from the Maker.  Such notice  shall
state the  intended  method of  disposition  of such  Conversion  Shares by such
Holder. If the Holder decides not to include all of the Conversion Shares in any
registration  statement  thereafter  filed  by  the  Maker,  such  Holder  shall
nevertheless continue to have the right to include such Conversion Shares in any
subsequent  registration statement or registration statements as may be filed by
the Maker with respect to offerings  of its  securities,  all upon the terms and
conditions set forth herein.

      7.  Event of  Default.  Upon the  occurrence  of any event of  default  as
described  below,  the  Holder  shall have the  remedies  set forth in Section 8
hereof, which remedies shall be exclusive:


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          (a) any  default,  whether  in whole or in  part,  shall  occur in the
payment to the Holder of principal,  interest or other item  comprising the Note
as and when due which shall continue for a period of fifteen  business (15) days
after the receipt of written  notice  thereof by the Maker;

          (b) the Maker shall (1) make a general  assignment  for the benefit of
its  creditors,  (2) apply for or  consent  to the  appointment  of a  receiver,
trustee,  assignee,  custodian sequestrator,  liquidator or similar official for
itself or any of its assets and  properties,  (3) commence a voluntary  case for
relief as a debtor under the United  States  Bankruptcy  Code,  (4) file with or
otherwise  submit to any  governmental  authority any petition,  answer or other
document seeking (A) reorganization, (B) an arrangement with creditors or (C) to
take  advantage  of any  other  present  or  future  applicable  law  respecting
bankruptcy,  reorganization,   insolvency,  readjustment  of  debts,  relief  of
debtors,  dissolution or liquidation, (5) file or otherwise submit any answer or
other  document  admitting or failing to contest the material  allegations  of a
petition  or other  document  filed or  otherwise  submitted  against  it in any
proceeding  under any such  applicable  law, or (6) be  adjudicated  bankrupt or
insolvent by a court of competent  jurisdiction;  or

          (c) any case,  proceeding  or other action shall be commenced  against
the Maker for the purpose of effecting, or an order, judgment or decree shall be
entered by any court of competent  jurisdiction  approving (in whole or in part)
anything specified in Section 7(b) hereof, or any receiver,  trustee,  assignee,
custodian,  sequestrator,  liquidator or other  official shall be appointed with
respect to the Maker, or shall be appointed to take or shall  otherwise  acquire
possession or control of all or a substantial  part of the assets and properties
of the Maker, and any of the foregoing shall continue unstayed and in effect for
any period of ninety (90) days.


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      8.  Exclusive  Remedies upon Event of Default.  Upon the  occurrence of an
event of default as described  in Section 7 hereof,  any Holder of this Note may
exercise one of the following  exclusive remedies by providing the Maker written
notice of the Holder's choice of remedies hereunder within fifteen (15) business
days  after the  occurrence  of an event of default  as  described  in Section 7
hereof and upon the expiration of any notice or cure period described herein:

          (a) The Holder of this Note  shall have the right to convert  all (but
not less than all) amounts due under this Note into Common  Stock in  accordance
with the conversion  procedures as set forth in Section 5(b) hereof.  The number
of shares of Common Stock into which this Note may be converted pursuant to this
Section  8(a) shall be  determined  by  dividing  (i) the sum of all amounts due
under this Note (including,  without  limitation,  all principal and accrued but
unpaid  interest) up to and including the Conversion  Date by (ii) Three Dollars
(US $3.00) per share (as adjusted in accordance  with Section 5(d)  hereof).  No
fractional shares of Common Stock or scrip representing  fractional shares shall
be issued upon  conversion  of this Note.  Instead of any  fractional  shares of
Common Stock which would  otherwise be issuable upon conversion of the Note, the
Maker shall pay to the Holder a cash adjustment in respect of such fraction; or

          (b) The Holder of this Note shall have the right to the  repayment  in
cash of all  amounts  due under this Note,  in which case such  Holder  shall be
entitled  to  receive a warrant  from the Maker  that  entitles  such  Holder to
purchase  from the Maker Ten  Thousand  (10,000)  shares of Common  Stock of the
Maker at a purchase  price per share of Five  Dollars (US $5.00) (as adjusted in
accordance with Section 5(d) hereof) for each month that such principal  balance
remains unpaid up to a maximum of six (6) months. Any warrants issuable pursuant


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to this Section  8(b) shall be issued to the Holder on the last  business day of
each month each such warrant is due.

      9.  Delay in  Exercise  of  Rights.  No delay on the part of the Holder in
exercising  any of its  options,  powers or  rights  nor any  partial  or single
exercise of its options, power or rights shall constitute a waiver thereof or of
any other option, power or right, and no waiver on the part of the Holder of any
of its options,  powers or rights shall constitute a waiver of any other option,
power or right.

      10. Waiver  of  Presentment.  The  Maker  hereby  waives  presentment  for
payment,  dishonor,  protest,  notice of protest and any demand  whatsoever with
respect to this Note.

      11. Governing Law.

          (a)  This  Note  and the  rights  of the  parties  hereunder  shall be
governed by and construed in  accordance  with the laws of the State of Florida,
without regard to its conflicts of law principles.  All parties hereto (1) agree
that any legal  suit,  action or  proceeding  arising out of or relating to this
note shall be instituted only in a Federal or state court in Miami-Dade  County,
Florida,  (2) waive any  objection  which they may now or hereafter  have to the
laying of the venue of any such suit, action or proceeding,  including,  without
limitation,  any  objection  based  on  the  assertion  that  such  venue  is an
inconvenient  forum  and (3)  irrevocably  submit  to the  jurisdiction  of such
Federal or state court in Miami-Dade County, Florida in any such suit, action or
proceeding.  All  parties  hereto  agree that the  mailing of any process in any
suit,  action or proceeding.  in accordance  with the notice  provisions of this
Note shall constitute personal service thereof.

          (b) THE MAKER  HEREBY  WAIVES  ANY RIGHT TO TRIAL BY JURY IN ANY LEGAL
PROCEEDING RELATED IN ANY WAY TO THIS NOTE.


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      12. Notices. All notices or other communications  required or permitted to
be given  pursuant to this Note shall be in writing and shall be  considered  as
duly given on (a) the date of delivery,  if delivered in person or by nationally
recognized  overnight  delivery  service or (b) ten (10) days  after  mailing if
mailed by certified  mail,  return  receipt  requested to the party  entitled to
receive  the same,  if to the  Holder,  at his or its  address  on the books and
records of the Maker, and if to the Maker, to Genetic  Vectors,  Inc., 5201 N.W.
77th Avenue,  Suite 100, Miami, Florida 33166,  Attention:  Mead M. McCabe, Jr.,
with a copy to Kirkpatrick & Lockhart LLP, Miami Center - 20th Floor,  201 South
Biscayne Boulevard, Miami, Florida 33131, Attention: Clayton E. Parker, Esq. Any
party may change its address by giving notice to the other party stating its new
address.  Commencing  on the tenth  (10th) day after the giving of such  notice,
such newly  designated  address shall be such party's address for the purpose of
all notices or other  communications  required or permitted to be given pursuant
to this Note.

      13. Amendment.  This Note shall not be amended  without the prior  written
consent of the Holder and the Maker.

                                      GENETIC VECTORS, INC.

                                      By:________________________________

                                      Its:_______________________________