Table 1.

Subclasses of ceramides identified in human fibroblasts and keratinocytes according to the nomenclature proposed by Masukawa [14].

CER Subclass	Fatty Acid	Sphingoid Base
CER[NDS]	non-hydroxy [N]	dihydrosphingosine [DS]
CER[NS]	non-hydroxy [N]	sphingosine [S]
CER[NP]	non-hydroxy [N]	phytosphingosine [P]
CER[ADS]	α-hydroxy [A]	dihydrosphingosine [DS]
CER[AS]	α-hydroxy [A]	sphingosine [S]
CER[AP]	α-hydroxy [A]	phytosphingosine [P]
CER[EOS]	esterified ω-hydroxy [EO]	sphingosine [S]