The Results of the GEO dataset, TCGA database (Additional file 1: Fig S7) and previous studies (Elashi 2019; Sasidharan Nair et al. 2018) showed that: compared with normal tissue and PBL samples from healthy controls, methylation status of PDCD-1 in tumor tissues and PBL samples from CRC patients were in concordance with transcriptomic expression in CRC: the more the hypomethylation, the higher the expression, but LAG-3 were not completely consistent in tissue and PBL samples. This evidence concerns the gene PDCD1 and neoplasm.