In contrast to CDKN2A, methylation of CDH1 promoter was more commonly encountered in PDC tissues in long-DM at a rate of 61% (20/33 subjects), 22% (13/59 subjects) in non-DM, and 18% (3/17 subjects) in short-DM in the order of frequency (p < 0.01 long-DM vs non-DM and short-DM). This evidence concerns the gene CDKN2A and diabetes mellitus.