Exhibit 4.1


 





 


ZQ|CERT#|COY|CLS|RGSTRY|ACCT#|TRANSTYPE|RUN#|TRANS# COMMON STOCK PAR
VALUE $0.0001 COMMON STOCK SEE REVERSE FOR CERTAIN DEFINITIONS Certificate Number Shares . XILIO THERAPEUTICS, INC. INCORPORATED UNDER
THE LAWS OF THE STATE OF DELAWARE ZQ00000000 INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE FACSIMILE SIGNATURE TO COME FACSIMILE
SIGNATURE TO COME President Secretary By AUTHORIZED SIGNATURE 6/18/2020 DEL AWAR E CO R PO RATE XILIO THERAPEUTIC S, INC. Xilio Therapeutics,
Inc. (hereinafter called the “Company”), transferable on the books of the Company in person or by duly authorized attorney,
upon surrender of this Certificate properly endorsed. This Certificate and the shares represented hereby, are issued and shall be held
subject to all of the provisions of the Certificate of Incorporation, as amended, and the By-Laws, as amended, of the Company (copies
of which are on file with the Company and with the Transfer Agent), to all of which each holder, by acceptance hereof, assents. This
Certificate is not valid unless countersigned and registered by the Transfer Agent and Registrar. Witness the facsimile seal of the Company
and the facsimile signatures of its duly authorized officers.ZQ|CERT#|COY|CLS|RGSTRY|ACCT#|TRANSTYPE|RUN#|TRANS# 98422T 10 0 DD-MMM-YYYY
* * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * *
* * * * * * * 000000* * * * * * * * * * * * * * * * * * * * * 000000* * * * * * * * * * * * * * ** Mr. Alexander David Sample **** Mr.
Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander
David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample ****
Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander
David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample ****
Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander
David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David
Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample
**** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample **** Mr. Alexander David Sample ****
Mr. Sample **** Mr. Sample **000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares***
*000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****
000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****0
00000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****00
0000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000
000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****0000
00**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****00000
0**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000
**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000*
*Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**
Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**Shares****000000**S
***ZERO HUNDRED THOUSAND ZERO HUNDRED AND ZERO*** MR. SAMPLE & MRS. SAMPLE & MR. SAMPLE & MRS. SAMPLE ZQ00000000 Certificate
Numbers 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890 1234567890/1234567890
Total Transaction Num/No. 123456 Denom. 123456 Total 1234567 MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 PO BOX 505006,
Louisville, KY 40233-5006 CUSIP/IDENTIFIER XXXXXX XX X Holder ID XXXXXXXXXX Insurance Value 1,000,000.00 Number of Shares 123456 DTC
12345678 123456789012345 THIS CERTIFICATE IS TRANSFERABLE IN CITIES DESIGNATED BY THE TRANSFER AGENT, AVAILABLE ONLINE AT www.computershare.com




 






     


     


    

 





 


XILIO THERAPEUTICS, INC. THE COMPANY WILL FURNISH WITHOUT CHARGE
TO EACH SHAREHOLDER WHO SO REQUESTS, A SUMMARY OF THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL OR OTHER
SPECIAL RIGHTS OF EACH CLASS OF STOCK OF THE COMPANY AND THE QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS OF SUCH PREFERENCES AND RIGHTS,
AND THE VARIATIONS IN RIGHTS, PREFERENCES AND LIMITATIONS DETERMINED FOR EACH SERIES, WHICH ARE FIXED BY THE CERTIFICATE OF INCORPORATION
OF THE COMPANY, AS AMENDED, AND THE RESOLUTIONS OF THE BOARD OF DIRECTORS OF THE COMPANY, AND THE AUTHORITY OF THE BOARD OF DIRECTORS
TO DETERMINE VARIATIONS FOR FUTURE SERIES. SUCH REQUEST MAY BE MADE TO THE OFFICE OF THE SECRETARY OF THE COMPANY OR TO THE TRANSFER
AGENT. THE BOARD OF DIRECTORS MAY REQUIRE THE OWNER OF A LOST OR DESTROYED STOCK CERTIFICATE, OR HIS LEGAL REPRESENTATIVES, TO GIVE THE
COMPANY A BOND TO INDEMNIFY IT AND ITS TRANSFER AGENTS AND REGISTRARS AGAINST ANY CLAIM THAT MAY BE MADE AGAINST THEM ON ACCOUNT OF THE
ALLEGED LOSS OR DESTRUCTION OF ANY SUCH CERTIFICATE.


The following abbreviations, when used in the inscription on the
face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN
COM -as tenants in common UNIF GIFT MIN ACT -............................................ Custodian................................................
(Cust) (Minor) TEN ENT -as tenants by the entireties under Uniform Gifts to Minors Act........................................................
(State) JT TEN -as joint tenants with right of survivorship UNIF TRF MIN ACT -............................................ Custodian
(until age................................) and not as tenants in common (Cust) .............................under Uniform Transfers
to Minors Act................... (Minor) (State) Additional abbreviations may also be used though not in the above list.


The IRS requires that the named transfer agent (“we”)
report the cost basis of certain shares or units acquired after January 1, 2011. If your shares or units are covered by the legislation,
and you requested to sell or transfer the shares or units using a specific cost basis calculation method, then we have processed as you
requested. If you did not specify a cost basis calculation method, then we have defaulted to the first in, first out (FIFO) method. Please
consult your tax advisor if you need additional information about cost basis. If you do not keep in contact with the issuer or do not
have any activity in your account for the time period specified by state law, your property may become subject to state unclaimed property
laws and transferred to the appropriate state. For value received,____________________________ hereby sell, assign and transfer unto
________________________________________________________________________________________________________________________________ ________________________________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________ _______________________________________________________________________________________________________________________
Shares _______________________________________________________________________________________________________________________ Attorney
Dated: __________________________________________ 20__________________ Signature:____________________________________________________________
Signature:____________________________________________________________ Notice: The signature to this assignment must correspond with
the name as written upon the face of the certificate, in every particular, without alteration or enlargement, or any change whatever.
PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING POSTAL ZIP
CODE, OF ASSIGNEE) of the common stock represented by the within Certificate, and do hereby irrevocably constitute and appoint to transfer
the said stock on the books of the within-named Company with full power of substitution in the premises. .