BAX (BCL2 Associated X) is a pro-apoptotic member of the BCL2 protein family, crucial in regulating apoptosis. It contains four Bcl-2 homology (BH1–BH4) domains and a C-terminal transmembrane domain. In healthy cells, BAX remains in the cytoplasm via interaction with anti-apoptotic proteins like BCL2L1 (Bcl-xL). Upon apoptotic stimuli, BAX undergoes a conformational change and translocates to the outer mitochondrial membrane, where it promotes apoptosis through two main mechanisms: interacting with the voltage-dependent anion channel (VDAC) to release cytochrome c, or forming oligomeric pores that permeabilize the membrane. Released cytochrome c activates caspase-3, triggering cell death. BAX is also a direct transcriptional target of p53 and plays a role in p53-mediated apoptosis, with p53 both regulating its expression and interacting with BAX to enhance its activity.