In most cancers, NRP1 and NRP2 expression was found to be positively correlated with immune checkpoint genes (CD274, CTLA4, HAVCR2, LAG3, PDCD1, PDCD1LG2, SIGLEC15, and TIGIT) (Figures 5(a) and 5(b)). This evidence concerns the gene SIGLEC15 and cancer.