Exhibit 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the 2017 Equity Incentive Plan and the 2017 Employee Stock Purchase Plan of Tocagen Inc. of our report dated March 9, 2018, with respect to the financial statements of Tocagen Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2017, filed with the Securities and Exchange Commission.
/s/ Ernst & Young LLP
San Diego, California
March 9, 2018
