EXHIBIT 23.3

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated March 12, 2007 relating to the financial statements of CombiMatrix Group (a division of Acacia Research Corporation), which appears in Acacia Research Corporation's Annual Report on Form 10-K for the year ended December 31, 2006.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Seattle, Washington

July 19, 2007