an N-acylsphing-4-enine + a 1,2-diacyl-sn-glycero-3-phosphocholine => a sphingomyelin + a 1,2-diacyl-sn-glycerol
an n-acylsphing-4-enine + a 1,2-diacyl-sn-glycero-3-phosphocholine => a sphingomyelin + a 1,2-diacyl-sn-glycerol