Endophilin-B1 (SH3GLB1) is a part of the endophilin family and highly expresses in heart, skeletal muscle, kidney and placenta. Endophilin B1 belongs to the B subgroup of the endophilin family which is needed for preservation of mitochondrial morphology and for the regulation of the outer mitochondrial membrane dynamics. SH3GLB1 is required for normal outer mitochondrial membrane dynamics. Furthermore, SH3GLB1 is required for coatomer-mediated retrograde transport in certain cells. SH3GLB1 interacts with SH3GLB2 and Bcl-2-associated X protein and involved in regulating apoptotic signaling pathways.