– ASAH2 (N-acylsphingosine amidohydrolase 2), also known as neutral ceramidase, is a type II integral membrane protein that can be cleaved to produce a soluble secreted protein. The enzyme is abundant in the brush border membranes of the intestine, and also expressed in several tissues such as kidney, brain and liver. The primary structure of ASAH2/neutral ceramidase is highly conserved from bacteria to humans, however, there is a clear difference in the molecular architecture. The murine ASAH2 possesses ‘amucin box’, a Ser/Thr/Pro-rich domain glycosylated with O-glycans which is necessary to retain the enzyme on the plasma membrane as a type II integral protein. The major physiological function of ASAH2/neutral ceramidase is the metabolism of dietary sphingolipids, and thus plays a role in the generation of messenger molecules such as sphingosine and sphingosine 1-phosphate.