Ownership Submission
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

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Clarus Lifesciences II, L.P.
  2. Issuer Name and Ticker or Trading Symbol
NanoString Technologies Inc [NSTG]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O CLARUS VENTURES,, 101 MAIN STREET, SUITE 1210
3. Date of Earliest Transaction (Month/Day/Year)
03/22/2019
(Street)

CAMBRIDGE, MA 02142
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction 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 03/22/2019   S   2,000,000 D $ 21.62 (1) 2,036,025 I See Footnotes (2) (3) (4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction 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
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(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

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Clarus Lifesciences II, L.P.
C/O CLARUS VENTURES,
101 MAIN STREET, SUITE 1210
CAMBRIDGE, MA 02142
    X    
Clarus Ventures II GP, L.P.
C/O CLARUS VENTURES
101 MAIN STREET, SUITE 1210
CAMBRIDGE, MA 02142
    X    
Blackstone Clarus II L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Holdings II L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Holdings I/II GP Inc
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Group L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Group Management L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
SCHWARZMAN STEPHEN A
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    

Signatures

 CLARUS LIFESCIENCES II, L.P., By: Clarus Ventures II GP, L.P., its GP, By: Blackstone Clarus II L.L.C., its GP, By: Blackstone Holdings II L.P., its managing member, By: Blackstone Holdings I/II GP Inc., its GP, By: /s/ John G. Finley, Title: CLO   03/22/2019
**Signature of Reporting Person Date

 CLARUS VENTURES II GP, L.P., By: Blackstone Clarus II L.L.C., its GP, By: Blackstone Holdings II L.P., its managing member, By: Blackstone Holdings I/II GP Inc., its GP, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 BLACKSTONE CLARUS II L.L.C., By: Blackstone Holdings II L.P., its managing member, By: Blackstone Holdings I/II GP Inc., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 BLACKSTONE HOLDINGS II L.P., By: Blackstone Holdings I/II GP Inc., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 BLACKSTONE HOLDINGS I/II GP INC., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 THE BLACKSTONE GROUP L.P., By: Blackstone Group Management L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 BLACKSTONE GROUP MANAGEMENT L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   03/22/2019
**Signature of Reporting Person Date

 /s/ Stephen A. Schwarzman   03/22/2019
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) This amount represents the $23.00 public offering price per share of common stock, par value $0.0001 per share, of NanoString Technologies, Inc. (the "Issuer"), less the underwriting discount of $1.38 per share.
(2) These securities are held directly by Clarus Lifesciences II, L.P. ("Clarus II"). Clarus Ventures II GP, L.P. ("Clarus II GP") is the sole general partner of Clarus II. Blackstone Clarus II L.L.C. is the sole general partner of Clarus GP. The sole member of Blackstone Clarus II L.L.C. is Blackstone Holdings II L.P. The sole general partner of Blackstone Holdings II L.P. is Blackstone Holdings I/II GP Inc. The controlling shareholder of Blackstone Holdings I/II GP Inc. is The Blackstone Group L.P. The sole general partner of The Blackstone Group L.P. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly-owned by Blackstone's senior managing directors and controlled by its founder, Stephen A. Schwarzman.
(3) Information with respect to each of the Reporting Persons is given solely by such Reporting Person, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person.
(4) Each of the Reporting Persons (other than Clarus II) disclaims beneficial ownership of the securities held by Clarus II, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, each of the Reporting Persons (other than Clarus II) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose.

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