POLG2 and adrenal cortex carcinoma: CDK6 and 9 other genes unrelated to proliferation, namely E2F3, E2F5, ORC2L, ORC4L, ORC5L, CDKN2B, POLG2, REV3L and SMARCAL1, belong to the expression cluster 2 (Supplementary Figure 1) and thus have similar expression profiles in ACC patients.