Adrenocortical carcinoma (ACC) is a rare tumor with an estimated incidence between 0.7 and 2.0 per million per year, and characterized by a heterogeneous prognosis mainly depending on initial tumor stage according to the European Network for the Study of Adrenal Tumors (ENSAT) classification [1], resection status [2,3] and Ki67 proliferation index [4,5,6]. The gene discussed is MKI67; the disease is adrenal cortex carcinoma.