Sec Form 4 Filing - GILBERTSON RYAN RANDALL @ Sun BioPharma, Inc. - 2018-05-16

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 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 GILBERTSON RYAN RANDALL 2. Issuer Name and Ticker or Trading Symbol Sun BioPharma, Inc. [ SNBP] 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) 1000 PARKER'S LAKE ROAD 3. Date of Earliest Transaction (MM/DD/YY) 05/16/2018 (Street) WAYZATA, MN55391 4. If Amendment, Date Original Filed (MM/DD/YY) 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 Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 555,538 D Common Stock 28,000 I Total Depth Foundation Common Stock 05/16/2018 C 47,025 A 47,025 I Northern Capital Partners I, LP

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Expirat ion Date Title Amount or Number of Shares Convertible Promissory Note $ 10.1 ( 2 ) 05/16/2018 C 200,000 ( 3 ) 03/17/2017 12/01/2018 Common Stock 19,802 $ 200,000 ( 3 ) 0 I Northern Capital Partners I, LP Warrants (right to buy) $ 5 05/16/2018 C 47,025 05/16/2018 05/16/2021 Common Stock 47,025 ( 1 ) 47,025 I Northern Capital Partners I, LP

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other GILBERTSON RYAN RANDALL 1000 PARKER'S LAKE ROAD WAYZATA, MN55391 X Signatures /s/ Ryan R. Gilbertson 05/29/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to the "alternate conversion" under the Convertible Promissory Note, approximately $211,616 of outstanding principal and accrued but unpaid interest converted into 47,025 units at a price equal to $4.50 per unit. Each unit consisted of one share of common stock and a warrant to purchase an additional share of common stock. ( 2 )Originally convertible into issuer common stock at a price of $10.10 per share upon holder's election. Because a "qualified offering" occurred, outstanding principal and accrued but unpaid interest would have automatically converted into common stock at a rate of $3.35 per share or, as elected, into units at a rate equal to a 10% discount to the price paid in the qualified offering. ( 3 )Represents original principal amount.

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).

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