Thus, in this study, we analyzed the data from a retrospective analysis involving Chinese patients with advanced ACC treated with mitotane for ≥3 months and investigated the effects of genotyping for CYP2B6, 3A4, and PXR to identify the factors contributing to the wide interindividual differences in the mean steady-state plasma trough concentration of mitotane. This evidence concerns the gene NR1I2 and adrenal cortex carcinoma.