PDCD1 and colorectal carcinoma: There were significant associations between hypermethylation of PDCD-1 and LAG-3 and reduced CRC risk in young subjects (< 60 years) (PDCD-1: OR = 0.441, 95% CI 0.289–0.673, P < 0.001; LAG-3: OR = 0.336, 95% CI 0.215–0.525, P < 0.001), as well as in old subjects (≥ 60 years) (PDCD-1: OR = 0.457, 95% CI 0.278–0.754, P < 0.001; LAG-3: OR = 0.584, 95% CI 0.368–0.926, P = 0.022) (Table 5).