**STOCK
        OPTION AGREEMENT**
  THIS
        STOCK OPTION AGREEMENT (“Agreement”) is made by and between LIXTE BIOTECHNOLOGY
        HOLDINGS, INC, a Delaware corporation (the “Company”), and GIL
        SCHWARTZBERG (the
“Optionee”).
  WHEREAS,
        Concurrently herewith, Optionee has entered into a Consulting Agreement with
        the
        Company (the “Consulting Agreement”).
  NOW,
        THEREFORE, in consideration of the mutual benefit to be derived herefrom
        and
        pursuant to the Consulting Agreement, the Company and Optionee agree as
        follows:
  1.  Grant
        of Option .
        The
        Company hereby grants to Optionee the right, privilege and option (“Option”) to
        purchase 1,000,000 shares of its common stock (“Stock”) at an exercise price of
        $1.00 per share, in the manner and subject to the conditions provided
        hereinafter.
  2.  Vesting
        and Exercise of Option .
        The
        Optionee shall be vested in 50% of the total number of shares subject to
        the
        Option as of the date of this Agreement; and the remaining shares subject
        to the
        Option shall vest on the first anniversary on the date of this Agreement.
        Any
        exercise may be with respect to any part or all of the shares then vested
        and
        exercisable pursuant to such Option.
  3.  Termination
        of Option .
        Except
        as otherwise provided in this Agreement, to the extent not previously exercised,
        the Option shall terminate upon the first to occur of any of the following
        events:
  a.  Four
        years from the date of the vesting of a particular tranche
        hereunder;
  b.  the
        date
        the Consulting Agreement is terminated; or
  c.  the
        breach by Optionee of any provision of this Agreement.
  4.  Method
        of Exercise .
        An
        Option shall be exercised by written notice to the Company by the Optionee
        (or
        successor in the event of death). Such written notice shall state the number
        of
        shares with respect to which the Option is being exercised and designate
        a time,
        during normal business hours of the Company, for the delivery thereof ("Exercise
        Date"), which time shall be at least ten days after the giving of such notice
        unless an earlier date shall have been mutually agreed upon. At the time
        specified in the written notice, the Company shall deliver to the Optionee
        at
        the principal office of the Company, or such other appropriate place as may
        be
        determined by the Board, a certificate or certificates for such shares.
        Notwithstanding the foregoing, the Company may postpone delivery of any
        certificate or certificates after notice of exercise for such reasonable
        period
        as may be required to comply with any applicable listing requirements of
        any
        securities exchange. In the event an Option shall be exercisable by any person
        other than the Optionee, the required notice under this Section shall be
        accompanied by appropriate proof of the right of such person to exercise
        the
        option. The option exercise price shall be payable in full on or before the
        option Exercise Date by full payment in cash or certified bank or cashier's
        check.
  
 5.  Restrictions
        on Exercise and Delivery .
        The
        exercise of each Option shall be subject to the condition that, if at any
        time
        the Board shall determine, in its sole and absolute discretion,
  a.  the
        satisfaction of any withholding tax or other withholding liabilities, is
        necessary or desirable as a condition of, or in connection with, such exercise
        or the delivery or purchase of Stock pursuant thereto,
  b.  the
        listing, registration, or qualification of any shares deliverable upon such
        exercise is desirable or necessary, under any state or federal law, as a
        condition of, or in connection with, such exercise or the delivery or purchase
        of shares pursuant thereto, or
  c.  the
        consent or approval of any regulatory body is necessary or desirable as a
        condition of, or in connection with, such exercise or the delivery or purchase
        of shares pursuant thereto,
  then
        in
        any such event, such exercise shall not be effective unless such withholding,
        listing, registration, qualification, consent or approval shall have been
        effected or obtained free of any conditions not acceptable to the Board.
        Optionee shall execute such documents and take such other actions as are
        required by the Board to enable it to effect or obtain such withholding,
        listing, registration, qualification, consent or approval. Neither the Company
        nor any officer or member of the Board or the Committee, shall have any
        liability with respect to the non-issuance or failure to sell shares as the
        result of any suspensions of exercisability imposed pursuant to this
        Section.
  6.  Nonassignability .
        Options
        may not be sold, pledged, assigned or transferred in any manner other than
        by
        will or by the laws of intestate succession, and may be exercised during
        the
        lifetime of Optionee only by Optionee. Any transfer by Optionee of any Option
        granted under this Agreement shall void such Option and the Company shall
        have
        no further obligation with respect to such Option. No Option shall be pledged
        or
        hypothecated in any way, nor shall any Option be subject to execution,
        attachment or similar process.
  7.  Restrictive
        Legends .
        Each
        certificate evidencing the shares acquired upon exercise of an Option hereunder,
        including any certificate issued to any transferee thereof, shall be imprinted
        with appropriate legends.
  8.  Rights
        as Shareholder .
        Neither
        Optionee nor his executor, administrator, heirs or legatees, shall be, or
        have
        any rights or privileges of a shareholder of the Company in respect of the
        Stock
        unless and until certificates representing such Stock shall have been issued
        in
        Optionee’s name.
  9.  Notices .
        Any
        notice to be given under the terms of this Agreement shall be addressed to
        the
        Company in care of its Secretary at its principal office, and any notice
        to be
        given to Optionee shall be addressed to such Optionee at the address maintained
        by the Company for such person or at such other address as the Optionee may
        specify in writing to the Company.
  10.  Binding
        Effect .
        This
        Agreement shall be binding upon and inure to the benefit of Optionee, his
        heirs
        and successors, and of the Company, its successors and assigns.
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 11.  Governing
        Law .
        This
        Agreement shall be governed by the laws of the State of Delaware.
  IN
        WITNESS WHEREOF, this Agreement is effective as of, and the date of grant
        shall
        be September 12, 2007.
  **LIXTE
                  BIOTECHNOLOGY HOLDINGS, INC**By:_________________________________
                Name:John
                  S. Kovach
                Title:President**OPTIONEE**____________________________________Gil
                  Schwartzberg
 
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