As a result, the higher Ki-67 index (HR = 3.16, 95% CI: 1.52-6.61, P = 0.002) and higher intensity of CD276 expression in tumor cells (HR = 2.8, 95% CI: 1.28-6.15, P = 0.01) were the only prognostic factors in the multivariate Cox model, suggesting that differential expression of CD276 in tumor cells is an independent OS factor in ACC, as well as the Ki-67 index. This evidence concerns the gene MKI67 and adrenal cortex carcinoma.