The secretory machinery required for the packaging of these exosomes is dependent on the generation of ceramide in the plasma membrane by neutral sphingomyelinase 2 (nSMase2; Fig. 2) [116], and, in a mouse breast cancer cell line, the ceramide‐dependent production of exosomes was required for tumor angiogenesis [117]. Here, SMPD3 is linked to breast carcinoma.