To investigate the role of CYP2B in lipid metabolism, a Cyp2b triple knockout mouse lacking Cyp2b9, Cyp2b10, and Cyp2b13 was developed using CRISPER/Cas9. Wildtype (WT) and Cyp2b-null mice were fed a normal diet (ND) or a 60% high-fat diet (HFD) for 10 weeks. RNA was extracted from the livers of male and female mice from all treatment groups and used for RNA seqencing. RNAseq data demonstrated that hepatic gene expression in ND-fed Cyp2b-null male mice is similar to HFD-fed WT mice, indicating that Cyp2b-null male mice are reacting as if they are receiving a HFD even if they are not. Gene ontology and KEGG pathways show perturbations in lipid metabolism pathways, including PUFA metabolism, fatty acid elongation, and glycerophospholipid metabolism. Overall design: Use RNA-sequencing to investigate the role of Cyp2b in hight-fat diet-induced obesity on a transcriptomic level, by comparing the livers of WT and Cyp2b-null mice fed a HFD for 10 weeks using Illumina technology.