Updated project metadata. Fatty acid amide hydrolase (FAAH) is an important enzyme for lipid metabolism and an interesting pharmacological target, given its role in anandamide breakdown. The FAAH-/- genotype is the most widely used mouse model to achieve complete abolition of this enzyme. In this paper we explore, by means of label-free SWATH proteomics, the changes in protein expression occurring in the liver of FAAH-/- mice. We identified several altered biological processes and pathways, like fatty acid synthesis and glycolysis, which explain the observed phenotype of this mouse. We also observed the alteration of other proteins, like carboxylesterases and S-methyltransferases, apparently not immediately related to FAAH, but known to have important biological roles.