The results of GO and KEGG revealed that these differently expressed proteins were associated with the regulation of cell–cell adhesion, chromosomal region, PI3K binding, regulation of DNA metabolic process, EGFR tyrosine kinase inhibitor resistance, FoxO signaling pathway, NF-κB signaling pathway, PD-L1 expression, and PD-1 checkpoint pathway in cancer. The gene discussed is PDCD1; the disease is cancer.