Indeed, immunohistochemistry confirmed negative p63 expression in almost all grade 3 cases (9/11, 82%), with only two high grade cases revealing strong and diffuse expression of p63 in solid areas, whereas all grade 1–2 ACC showed positive p63 expression with a strong nuclear staining in > 30% of tumor cells (100% positive in grade I and II vs 18% in grade III, Chi-squared test p-value < 0.01) (Supplementary Table S3, Fig. 2B). This evidence concerns the gene TP63 and adrenal cortex carcinoma.