Ownership Submission
FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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 *
  Carusi Michael A
2. Date of Event Requiring Statement (Month/Day/Year)
01/31/2007
3. Issuer Name and Ticker or Trading Symbol
XTENT INC [XTNT]
(Last)
(First)
(Middle)
1000 WINTER STREET, SUITE 3700
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

WALTHAM, MA 02451
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Series B Convertible Preferred Stock   (1)   (7) Common Stock 10,828 $ 0 (1) I (8) By ATV Entrepreneurs VI, L.P.
Series C Convertible Preferred Stock   (1)   (7) Common Stock 9,883 $ 0 (1) I (8) By ATV Entrepreneurs VI, L.P.
Series D Convertible Preferred Stock   (1)   (7) Common Stock 4,997 $ 0 (1) I (8) By ATV Entrepreneurs VI, L.P.
Series B Convertible Preferred Stock   (2)   (7) Common Stock 169,643 $ 0 (2) I (8) By Advanced Technology Ventures VI, L.P.
Series C Convertible Preferred Stock   (2)   (7) Common Stock 154,849 $ 0 (2) I (8) By Advanced Technology Ventures VI, L.P.
Series D Convertible Preferred Stock   (2)   (7) Common Stock 78,284 $ 0 (2) I (8) By Advanced Technology Ventures VI, L.P.
Series B Convertible Preferred Stock   (3)   (7) Common Stock 6,036 $ 0 (3) I (9) By ATV Entrepreneurs VII, L.P.
Series C Convertible Preferred Stock   (3)   (7) Common Stock 5,529 $ 0 (3) I (9) By ATV Entrepreneurs VII, L.P.
Series D Convertible Preferred Stock   (3)   (7) Common Stock 2,794 $ 0 (3) I (9) By ATV Entrepreneurs VII, L.P.
Series B Convertible Preferred Stock   (4)   (7) Common Stock 40,644 $ 0 (4) I (9) By Advanced Technology Ventures VII (B), L.P.
Series C Convertible Preferred Stock   (4)   (7) Common Stock 37,229 $ 0 (4) I (9) By Advanced Technology Ventures VII (B), L.P.
Series D Convertible Preferred Stock   (4)   (7) Common Stock 18,821 $ 0 (4) I (9) By Advanced Technology Ventures VII (B), L.P.
Series B Convertible Preferred Stock   (5)   (7) Common Stock 19,536 $ 0 (5) I (9) By Advanced Technology Ventures VII (C), L.P.
Series C Convertible Preferred Stock   (5)   (7) Common Stock 17,895 $ 0 (5) I (9) By Advanced Technology Ventures VII (C), L.P.
Series D Convertible Preferred Stock   (5)   (7) Common Stock 9,046 $ 0 (5) I (9) By Advanced Technology Ventures VII (C), L.P.
Series B Convertible Preferred Stock   (6)   (7) Common Stock 1,012,820 $ 0 (6) I (9) By Advanced Technology Ventures VII, L.P.
Series C Convertible Preferred Stock   (6)   (7) Common Stock 927,748 $ 0 (6) I (9) By Advanced Technology Ventures VII, L.P.
Series D Convertible Preferred Stock   (6)   (7) Common Stock 469,021 $ 0 (6) I (9) By Advanced Technology Ventures VII, L.P.

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Carusi Michael A
1000 WINTER STREET, SUITE 3700
WALTHAM, MA 02451
  X      

Signatures

/s/ Michael A. Carusi 01/31/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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) The reported securities are convertible at any time at the option of ATV Entrepreneurs VI, L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(2) The reported securities are convertible at any time at the option of Advanced Technology Ventures VI, L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(3) The reported securities are convertible at any time at the option of ATV Entrepreneurs VII, L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(4) The reported securities are convertible at any time at the option of Advanced Technology Ventures VII (B), L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(5) The reported securities are convertible at any time at the option of Advanced Technology Ventures VII (C), L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(6) The reported securities are convertible at any time at the option of Advanced Technology Ventures VII, L.P., but automatically convert into shares of Common Stock on a 1-for-1 basis immediately prior to the closing of the Issuer's initial public offering, estimated to be on or about February 6, 2007.
(7) Not applicable.
(8) Mr. Carusi is a managing member of ATV Associates VI, L.L.C., the general partner of ATV Entrepreneurs VI, L.P. and Advanced Technology Ventures VI, L.P. Mr. Carusi disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein.
(9) Mr. Carusi is a managing member of ATV Associates VII, L.L.C., the general partner of ATV Entrepreneurs VII, L.P., Advanced Technology Ventures VII (B), L.P., Advanced Technology Ventures VII (C), L.P. and Advanced Technology Ventures VII, L.P. Mr. Carusi disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein.
 
Remarks:
The Date of Event is based upon the date of effectiveness of the Issuer's Registration Statement on Form S-1 filed in connection with the Issuer's initial public offering, estimated to be on or about January 31, 2007.

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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