The pooled ORs suggested no significant correlation between the PD-1.5 genotype and cancer susceptibility in all genetic models (T vs. C: OR = 0.99, 95% CI = 0.90-1.09, P = 0.807; TT vs. CC: OR = 0.93, 95% CI = 0.79-1.10, P = 0.386; CT vs. CC: OR = 1.05, 95% CI = 0.92-1.21, P = 0.476; TT+CT vs. CC: OR = 1.03, 95% CI = 0.90-1.17, P = 0.694; TT vs. CT+CC: OR = 0.92, 95% CI = 0.78-1.08, P = 0.288, Figure 2 and Table 2). Here, PDCD1 is linked to cancer.