CD63 and neoplasm: These include: (1) developing CD63-blocking antibodies or small-molecule inhibitors to interfere with exosome biogenesis or uptake; (2) employing inhibitors of exosome biogenesis or secretion, such as molecules targeting neutral sphingomyelinase 2 (nSMase2) or key Rab GTPases; and (3) using pharmacological inhibitors of lactate transporters, primarily monocarboxylate transporters 1 and 4 (MCT1/4), to impede lactate efflux from tumor cells or its uptake by immune cells.