SMPD1 and neoplasm: A good pathologic response was defined by a CAP score of 0 or 1 and was seen in 43.5% of patients not on co-medication with a functional inhibitor of the acid sphingomyelinase compared to 17.9% of patients on a functional inhibitor of the acid sphingomyelinase co-medication during neoadjuvant therapy (Fig. 3), suggesting that inhibition of the acid sphingomyelinase inhibits the tumor response to neoadjuvant treatment.