A large majority of the sex differences in mouse and rat liver are regulated by GH [49], and correspondingly, a large fraction (75–77%) of the mouse and rat orthologs of sex-biased genes of human liver were characterized by pituitary hormone-dependence in mouse and/or rat liver; these include three of the four sex-biased human liver genes directly linked to monogenic disorders of lipid metabolism (Apoa5, Abca1, Lipc). Here, APOA5 is linked to metabolic process.