BAX (BCL2-associated X protein) is a pro-apoptotic executor that regulates mitochondrial outer membrane permeabilization (MOM) and cell death 1. Under physiological conditions, BAX remains largely cytosolic through continuous retrotranslocation from mitochondria mediated by anti-apoptotic proteins like BCL2L1, preventing accumulation at the MOM 1. Upon stress signals, BAX undergoes conformational changes and translocates to mitochondria, where it oligomerizes with BAK to form apoptotic pores that release cytochrome c, triggering caspase-3 activation and apoptosis 2. BAX and BAK display distinct oligomerization kinetics, with BAK assembling rapidly into smaller structures while recruiting and accelerating BAX into progressively larger pores; this coordinated assembly determines mitochondrial content release rates, including mtDNA, affecting downstream inflammatory signaling 2. Dysregulation of BAX expression has significant clinical implications: reduced BAX expression correlates with aneuploidy in preimplantation embryos 3, while elevated BAX expression associates with poor prognosis across multiple cancer types and correlates with immune infiltration and immunotherapy efficacy 4. BAX function requires coordination with VDAC2, which can either inhibit or facilitate BAX activity depending on cellular context 5. These characteristics position BAX as both a critical homeostatic regulator and a promising therapeutic target for cancer and apoptosis-related diseases.