The intrinsic pathway of apoptosis is tightly regulated by the Bcl-2 family of proteins. This family includes both pro-apoptotic members (e.g., Bax, Bak) and anti-apoptotic members (e.g., Bcl-2, Bcl-xL). The balance between these opposing forces determines the cell's fate. Anti-apoptotic proteins work by sequestering pro-apoptotic proteins or directly inhibiting their activity, thereby preventing the initiation of apoptosis.
