Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Choi Jung	2. Issuer Name and Ticker or Trading Symbol Global Blood Therapeutics, Inc. [ GBT ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                      _____ 10% Owner __ X __ Officer (give title below)      _____ Other (specify below) See Remarks
(Last)          (First)          (Middle) C/O GLOBAL BLOOD THERAPEUTICS, INC., 171 OYSTER POINT BLVD., SUITE 300	3. Date of Earliest Transaction (MM/DD/YYYY) 5/17/2018
(Street) SOUTH SAN FRANCISCO, CA 94080 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	5/17/2018		S (1)		1600   (2)	D	$48.25	136077	D
Common Stock	5/17/2018		M		198	A	$3.40	136275	D
Common Stock	5/17/2018		M		601	A	$3.40	136876	D
Common Stock	5/17/2018		M		601	A	$3.40	137477	D
Common Stock	5/17/2018		S (1)		1400	D	$48.25	136077	D
Common Stock								25000	I	By Trust

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$3.40	5/17/2018		M			198	(3)	4/8/2025	Common Stock	198	$0.00	74964	D
Stock Option (Right to Buy)	$3.40	5/17/2018		M			601	(4)	4/8/2025	Common Stock	601	$0.00	2675	D
Stock Option (Right to Buy)	$3.40	5/17/2018		M			601	(5)	4/8/2025	Common Stock	601	$0.00	2675	D

Explanation of Responses:
(1)	This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person.
(2)	These shares of Common Stock were subject to the Issuer's right of repurchase, which lapsed with respect to 25% of the shares on April 6, 2016 and in 12 equal quarterly installments thereafter.
(3)	25% of the shares subject to this option vested and became exercisable on April 6, 2016 and the remaining shares subject to this option shall vest and become exercisable in 12 equal quarterly installments thereafter.
(4)	On April 9, 2015, the Reporting Person was granted an option to purchase 37,142 shares of Common Stock under the Issuer's 2012 Stock Option and Grant Plan, the vesting of which was subject to various conditions (other than the passage of time and continued employment) that were not tied to the market price of the Issuer's securities. On March 10, 2016, one of the conditions was deemed to be achieved, resulting in the vesting and exercisability of 9,286 of the shares underlying such option.
(5)	On April 9, 2015, the Reporting Person was granted an option to purchase 37,142 shares of Common Stock under the Issuer's 2012 Stock Option and Grant Plan, the vesting of which was subject to various conditions (other than the passage of time and continued employment) that were not tied to the market price of the Issuer's securities. On September 29, 2016, one of the conditions was deemed to be achieved, resulting in the vesting and exercisability of 9,286 of the shares underlying such option.

Remarks: Chief Business and Strategy Officer

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Choi Jung C/O GLOBAL BLOOD THERAPEUTICS, INC. 171 OYSTER POINT BLVD., SUITE 300 SOUTH SAN FRANCISCO, CA 94080			See Remarks

Signatures
Lesley Ann Calhoun, as Attorney-in-Fact		5/21/2018
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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