pGL3-OATP1B1, pTracer-hLXRα, and internal reference Renilla luciferase plasmid pRL-TK vector were purchased from Tsingke (Nanjing, China). The direct binding of LXRα to the OATP1B1 5′UTR was described in previous research containing LXRα response element (−128 to + 53 bp)[10]. Herein, HepG2 cells were seeded in 6‐well plates at a density of 7.5 × 10⁴ cells/well. After 24 hours, the cells were transfected with corresponding plasmids with Lipofectamine 3000 transfection reagent following the manufacturer’s protocol. The empty pTracer plasmid was used as a control. Afterward, cells were incubated by 0.1% DMSO, 400 nM DXM, 10 μM GW3965, or 400 nM DXM combined with 10 μM GW3965 for 3 days. Finally, the cells were processed using the dual-luciferase reporter assay system (Yeasen, Shanghai, China) based on the manufacturer’s protocol.