SMPD2 and breast carcinoma: The observation was in line with the previous report suggesting the treatment of human breast cancer cell line SKBR-3 with 5 μM GW4869 or siRNA against sphingomyelin phosphodiesterase 2/3 (also known as nSMase) resulted in a significant reduction of < 100 nm sized vesicles and increased quantities of vesicles with a size range of 100-200 nm; while overexpression of sphingomyelin phosphodiesterase-3 (also known as nSMase2) decreased the amount of larger-sized (100-200 nm) vesicles[47].