SMPD3 initiates vesicle budding, Rab27 oversees the fusion of MVE with the plasma membrane, the endosomal sorting complex required for transport (ESCRT) manages MVE maturation, and neutral sphingomyelinase type 2 (nSMase2) and Rab27 regulate exosome secretion.[121] The process begins with tumor cell membranes forming endosomes that translocate mPD‐L1 into the cytoplasm via the clathrin‐mediated endocytic pathway. Here, SMPD3 is linked to neoplasm.