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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1. Name and Address of Reporting Person * William Blair Capital Management VII, LLC   2. Issuer Name and Ticker or Trading Symbol CRYOCOR INC [CRYO] 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) 303 W. MADISON SUITE 2500 3. Date of Earliest Transaction (Month/Day/Year) 04/24/2007 (Street) CHICAGO, IL 60606 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 (1) 04/24/2007   P   96,553 (2) A $ 5.14 1,944,961 (3) I See footnote (4)

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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

Common Stock Warrants (Right to Buy)

$ 5.14

04/24/2007

P

53,103 (5)

10/24/2007

04/24/2012

Common Stock

53,103

$ 0.07

53,103

I

See footnote (4)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
William Blair Capital Management VII, LLC 303 W. MADISON SUITE 2500 CHICAGO, IL 60606		X
William Blair Capital Management VII, LP 303 W. MADISON SUITE 2500 CHICAGO, IL 60606		X
BLAIR WILLIAM CAPITAL PARTNERS VII QP LP 303 W. MADISON SUITE 2500 CHICAGO, IL 60606		X
BLAIR WILLIAM CAPITAL PARTNERS VII LP 303 W. MADISON SUITE 2500 CHICAGO, IL 60606		X

Signatures

Arda M. Minocherhomjee, Managing Director of William Blair Capital Management VII, L.L.C.		04/26/2007
**Signature of Reporting Person		Date
Arda M. Minocherhomjee, Managing Director of William Blair Capital Management VII, L.L.C., the general partner of William Blair Capital Management VII, L.P		07/14/2005
**Signature of Reporting Person		Date
Arda M. Minocherhomjee, Managing Director of William Blair Capital Management VII, L.L.C., the general partner of William Blair Capital Management VII, L.P., the general partner of William Blair Capital Partners VII QP, L.P.		07/14/2005
**Signature of Reporting Person		Date
Arda M. Minocherhomjee, Managing Director of William Blair Capital Management VII, L.L.C., the general partner of William Blair Capital Management VII, L.P., the general partner of William Blair Capital Partners VII, L.P.		07/14/2005
**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)	The Designated Filer is executing this report on behalf of William Blair Capital Management VII, L.L.C., William Blair Capital Management VII, L.P., William Blair Capital Partners VII QP, L.P. and William Blair Capital Partners VII, L.P. (collectively, the "Reporting Persons"), each of whom has authorized it to do so; each of the Reporting Persons disclaim beneficial ownership of the Issuer?s securities to the extent it exceeds such Reporting Person?s pecuniary interest.
(2)	The shares were purchased as follows: 92,970 by William Blair Capital Partners VII QP, L.P. and 3,583 shares by William Blair Capital Partners VII, L.P.
(3)	Represents 1,872,801 shares beneficially owned by William Blair Capital Partners VII QP, LP and 72,160 shares beneficially owned by William Blair Capital Partners VII LP.
(4)	The amount shown in Table I represents the beneficial ownership of the Issuer?s equity securities by William Blair Capital Partners VII QP, L.P. and William Blair Capital Partners VII, L.P., a portion of which may be deemed attributable to William Blair Capital Management VII, L.L.C. and William Blair Capital Management VII, L.P., because William Blair Capital Management VII, L.P. is the general partner of William Blair Capital Partners VII QP, L.P. and William Blair Capital Partners VII, L.P. and William Blair Capital Management VII, L.L.C. is the general partner of William Blair Capital Management VII, L.P. The actual pro rata portion of such beneficial ownership that may be deemed attributable to such Reporting Person is not readily determinable because it is subject to several variables.
(5)	The warrants were purchased and are held as follows: 51,133 by William Blair Capital Partners VII QP, L.P. and 1,970 by William Blair Capital Partners VII, L.P.

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