Rabbit Anti-Human ACER1 polyclonal antibody for WB. Ceramides are synthesized during epidermal differentiation and accumulate within the interstices of the stratum;corneum, where they represent critical components of the epidermal permeability barrier. Excess cellular ceramide can;trigger antimitogenic signals and induce apoptosis, and the ceramide metabolites sphingosine and;sphingosine-1-phosphate (S1P) are important bioregulatory molecules. Ceramide hydrolysis in the nucleated cell layers;regulates keratinocyte proliferation and apoptosis in response to external stress. Ceramide hydrolysis also occurs at;the stratum corneum, releasing free sphingoid base that functions as an endogenous antimicrobial agent. ACER1 is;highly expressed in epidermis and catalyzes the hydrolysis of very long chain ceramides to generate sphingosine;(Houben et al., 2006 (PubMed 16477081); Sun et al., 2008 (PubMed 17713573)).