In accordance with our findings on strong correlations with larger tumor size and survival outcomes, RRM2 was also previously found to be well correlated with Ki67 labeling index in ACC samples, and was already considered as a potential pharmaceutical target in ACC, as RRM2 was also found to be upregulated in NCI-H295 upon gemcitabine treatment [10]. This evidence concerns the gene MKI67 and adrenal cortex carcinoma.