PDCD1 and colorectal carcinoma: We therefore carried out this study to discover significantly differentially methylated CpG sites (DMCs) of PDCD-1 and LAG-3 using the GSE51032 dataset from the European Prospective Investigation into Cancer and Nutrition (EPIC) study and then screened the DMCs of the two genes located in CpG island and had the least P value as the candidate CpG sites to further explore the relationship between the methylation of the two genes and CRC risk in the case–control study.