PDCD1 and neoplasm: With the advent of the era of tumor immunotherapy, anti-EGFR therapy of colorectal cancer has also ushered in great opportunities, such as whether ICIs which include anti-PD-1(Programmed Cell Death 1)/PDL-1 (Programmed Cell Death Ligand 1)/CTLA-4 (Cytotoxic T-Lymphocyte-Associated Protein 4) antibody combined to anti-EGFR treatment could improve effectiveness and translate into patient survival benefits further.