Phoenix Biotech Acquisition Corp. (NASDAQ:PBAXW) operates as a blank check company, or special purpose acquisition company (SPAC), whose primary purpose is to effect a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses, principally in the biotechnology sector; it has no current operating revenues or significant products or services beyond pursuing such transactions. Incorporated in 2021 and headquartered in Oakland, California, with subsequent operational addresses noted in South San Francisco and Philadelphia, the company targets biotechnology and life sciences firms developing therapeutics or diagnostics. In February 2024, Phoenix Biotech completed a definitive business combination with CERo Therapeutics, Inc., resulting in the combined entity operating as CERo Therapeutics Holdings, Inc., with PBAX common stock and warrants renamed and continuing to trade under adjusted symbols, while the company anticipates initiating clinical trials for CER-1236, an engineered T cell therapy for hematologic malignancies and solid tumors; this merger followed high shareholder redemptions of approximately 99.5% and included a $2 million PIPE financing, marking its principal recent strategic shift to public company status for the immunotherapy-focused target.