PER2 and steatosis: We discovered that dietary CLA supplementation for 28 days already caused alterations of the circadian rhythm process, including the key clock genes, Per1, Per2, Crem, Clock, Arntl, Bhlhe41, and Cry1 in the liver of mice with the onset of steatosis, while high-fat diet has been shown to induce metabolic abnormalities involving the NR RORα and REV-ERBα, and affects the expression of Clock and Bmals during 12 weeks of experiment (42).