PMAIP1 (Phorbol-12-Myristate-13-Acetate-Induced Protein 1): PMAIP1, also known as Noxa, is a pro-apoptotic protein that plays a key role in regulating programmed cell death (apoptosis). It functions within the intrinsic apoptosis pathway and helps trigger cell death in response to cellular stress. PMAIP1 has important implications in cancer therapy, as its activation can increase the sensitivity of cancer cells to apoptosis-inducing treatments.