PDCD1 and cancer: Several important variants in the gene have been identified, such as the PDCD-1.5 (rs2227981) polymorphism, PDCD-1.9 (rs2227982), and so on.[5,9] Up to now, the associations between polymorphisms in the PDCD1 gene and the risk of cancer were still inconclusive; thus, we performed the current meta-analysis.