PPIG and Hepatic fibrosis: Of the 20 genes that showed consistent sex-specific expression across all eight strains, eight genes were active in steroid and drug/foreign chemical metabolism (Cyp, Gst, Fmo, Aox, and Hsd family members), three were enzymes of fatty acid biosynthesis and metabolism (Elovl3, Acot3, Cyp4a12a), two were complement genes (C8b, C9), and two were involved in liver fibrosis (Prom1, Rtn4; [74, 75]).