CDKN2A and colorectal carcinoma: To evaluate the clinical significance of these observations, we analyzed human CRC data from The Cancer Genome Atlas (TCGA) and found a weak but significant positive correlation between p16 epimutation and PDL1 mRNA expression (n = 633, R = 0.21, P = 0.00004 by Spearman’s rank correlation test) (Fig. S2A).