ALDH1L1 and neoplasm: Of note, changes in the levels of several of those metabolites (N1-acetylspermidine, glycocholic acid, 7-methylguanine [65], serine, glycine, linoleic acid [75], hippurate, taurocholate, glycocholate, phytosphingosine, and palmitic acid [69]) in response to DEN exposure in Aldh1l1 KO mice compared to WT mice are in agreement with the effect of enzyme loss on tumor proliferation.