CDP-ethanolamine + an N-acylsphing-4-enine => an N-acylsphing-4-enine 1-phosphoethanolamine + CMP + H(+)
cdp-ethanolamine + an n-acylsphing-4-enine => an n-acylsphing-4-enine 1-phosphoethanolamine + cmp + h(+)