MKI67 and adrenal cortex carcinoma: Next, we analyzed MELK protein expression and its relation to Ki67, a marker of proliferation commonly used as a prognostic indicator in ACC, by IHC in human adrenal samples from the NIH cohort and found a linear and, positive correlation (Spearman’s correlation coefficient 0.5049, p = 0.04) (Fig. 2B, C) [18, 19].