The BCL-2 family of proteins, originally characterized for their roles in controlling mitochondrial membrane integrity and apoptosis, has expanded its functions to include numerous cellular pathways. This review discusses the mechanisms and functions of the BCL-2 family in the context of these pathways, highlighting the complex integration and regulation of the BCL-2 family in cell fate decisions. The BCL-2 family is classified into antiapoptotic and proapoptotic members, with antiapoptotic proteins containing four BCL-2 homology domains (BH1-4) and proapoptotic proteins divided into effector and BH3-only proteins. The regulation of BCL-2 family members and their interactions is crucial for maintaining cellular homeostasis and survival. The review also explores the structural considerations of the BCL-2 core, the regulation of mitochondrial morphology and ER signaling, the role of BCL-2 proteins in autophagy, and the pharmacological regulation of BCL-2 family members. The BCL-2 family's functions extend beyond apoptosis, impacting metabolism and other cellular processes, and future research aims to further integrate these functions into cell physiology.The BCL-2 family of proteins, originally characterized for their roles in controlling mitochondrial membrane integrity and apoptosis, has expanded its functions to include numerous cellular pathways. This review discusses the mechanisms and functions of the BCL-2 family in the context of these pathways, highlighting the complex integration and regulation of the BCL-2 family in cell fate decisions. The BCL-2 family is classified into antiapoptotic and proapoptotic members, with antiapoptotic proteins containing four BCL-2 homology domains (BH1-4) and proapoptotic proteins divided into effector and BH3-only proteins. The regulation of BCL-2 family members and their interactions is crucial for maintaining cellular homeostasis and survival. The review also explores the structural considerations of the BCL-2 core, the regulation of mitochondrial morphology and ER signaling, the role of BCL-2 proteins in autophagy, and the pharmacological regulation of BCL-2 family members. The BCL-2 family's functions extend beyond apoptosis, impacting metabolism and other cellular processes, and future research aims to further integrate these functions into cell physiology.