Analysis of KEGG pathway enrichment showed that MAP3K8 co-expressed genes were highly enriched in the MAPK signaling pathway, NF-kappa B signaling pathway, Toll-like receptor signaling pathway, cytokine–cytokine receptor interaction, chemokine signaling pathway, T helper 2 (Th2) cell differentiation, cell adhesion molecules, programmed death-ligand 1 (PD-L1) expression, and programmed death-1 (PD-1) checkpoint pathway in cancer (Figures 4E, F). The gene discussed is PDCD1; the disease is cancer.