PDCD1 and neoplasm: Several significant interactions (such as SPP1-CD44, CXCL12-CXCR4 and PDCD1LG2-PDCD1) were inferred among TAMs, tumor cells and CD8+ T cells, which involved the activation of ERK, TGF-β and NF-κB signaling pathways in tumor cells and the negative regulation of activated T cell proliferation.