431246 SM sphingomyelin 1911 1640174 SPH sphingomyelin 100 1641856 SPM sphingomyelin 84 436670 SP sphingomyelin 25 1639970 sph sphingomyelinase 7 3473705 SphM sphingomyelin 4 1605508 SGM sphingomyelin 1 1608986 SHP sphingomyelin 1 1623055 SME sphingomyelin 1 1629080 SMY sphingomyelin 1 1640401 SPG sphingomyelin 1