AP5M1 (adaptor related protein complex 5 subunit mu 1) is a subunit of the AP-5 vesicular trafficking complex involved in endosomal transport and lysosomal homeostasis. As part of AP-5, AP5M1 localizes to late endosomes and the Golgi apparatus 1 and functions in intracellular cargo sorting and trafficking 2. The protein regulates yolk vesicle formation during oocyte maturation 3 and maintains proper cellular homeostasis through lysosomal pathways 1. Beyond trafficking functions, AP5M1 exhibits pro-apoptotic activity independent of its structural role. The adaptin domain of AP5M1 mediates cell death, with caspase-3 cleaving AP5M1 during TRAIL-induced apoptosis 4. AP5M1 induces apoptosis in cervical cancer cells through BAX-dependent mitochondrial pathways, with strong positive correlation between AP5M1 and BAX expression in cervical tissues 5. Clinically, bi-allelic loss-of-function variants in AP5M1 cause recessive inherited retinal disease characterized by macular degeneration 1. The retinal pigment epithelium's dependence on robust lysosomal and phagocytic activity explains its particular vulnerability to AP5M1 dysfunction. These findings establish AP-5 as essential for retinal homeostasis and identify AP5M1 as both a trafficking protein and a potential therapeutic target in cancer.