The function of Ensembl gene identifier ENSG00000188611 (ASAH2, N-acylsphingosine amidohydrolase 2) is as follows. Plasma membrane ceramidase that hydrolyzes sphingolipid ceramides into sphingosine and free fatty acids at neutral pH (PubMed:10781606, PubMed:16229686, PubMed:26190575). Ceramides, sphingosine, and its phosphorylated form sphingosine-1-phosphate are bioactive lipids that mediate cellular signaling pathways regulating several biological processes including cell proliferation, apoptosis and differentiation (PubMed:15946935, PubMed:19345744, PubMed:24798654). Also catalyzes the reverse reaction allowing the synthesis of ceramides from fatty acids and sphingosine (PubMed:11278489, PubMed:17475390). Together with sphingomyelinase, participates in the production of sphingosine and sphingosine-1- phosphate from the degradation of sphingomyelin, a sphingolipid enriched in the plasma membrane of cells (PubMed:16061940). Also participates in the hydrolysis of ceramides from the extracellular milieu allowing the production of sphingosine-1-phosphate inside and outside cells (By similarity). This is the case for instance with the digestion of dietary sphingolipids in the intestinal tract (By similarity). {ECO:0000250|UniProtKB:Q9JHE3, ECO:0000269|PubMed:10781606, ECO:0000269|PubMed:11278489, ECO:0000269|PubMed:15946935, ECO:0000269|PubMed:16061940, ECO:0000269|PubMed:16229686, ECO:0000269|PubMed:17475390, ECO:0000269|PubMed:19345744, ECO:0000269|PubMed:24798654, ECO:0000269|PubMed:26190575}.