ASAH1 and neoplasm: We therefore determined mRNA expression levels of genes coding for key enzymes of the de novo CER synthesis pathway (serine palmitoyl transferases Sptlc1, Sptlc2; 3‐ketosphinganine reductase Kdsr; CER synthases Cers5, Cers6, Cers2; dihydroceramide desaturases Degs1, Degs2) and of the salvage pathway (i.e. sphingomyelin hydrolysis into CER by acid sphingomyelinase Smpd1), as well as CER degradation (Asah1) in metabolic organs and tumours from NC26, C26‐precx, and C26‐cx mice.