Atorvastatin calcium tablet was provided by Pfizer (USA). Dexamethasone acetate tablet was provided by Xinyi (China). Atorvastatin calcium (ATV, 99.4% purity), o- hydroxy atorvastatin calcium (o- ATV, 97.6% purity), and p- hydroxy atorvastatin calcium (p- ATV, 98.7% purity) were all supplied by TLC PharmaChem company (Canada). Meanwhile, d5-atorvastatin calcium (d5-ATV, 96% purity, 99.5% isotopic content) was purchased from Toronto Research Chemicals Company (Canada). Rosuvastatin (RSV, 98% purity) was obtained from Solarbio (China). GW3965 was provided by Selleck (USA). Moreover, the Dual-luciferase reporter assay system was purchased from Yeasen (China). Furthermore, Lipofectamine 3000 was purchased from Thermo Fisher Scientific (USA).