Subsequently, the N‐acyl group in ceramide is removed by one of five different ceramidases which include the acid ceramidase ASAH1/AC, the neutral ceramidase ASAH2/NC, and the alkaline ceramidases 1–3 (ACER1, ACER2, ACER3) of which the lysosomal ceramidase ASAH1 is probably the most important as exemplified by the clinical consequences of ASAH1 deficiency (Farber disease). The gene discussed is ACER1; the disease is Farber lipogranulomatosis.