Immunotherapy strategies (e.g., immune checkpoint inhibition by anti–programmed death-1 (PD-1)/anti–PD-1 ligand 1 (PD-L1) and anti-CTLA-4 therapy, and adoptive cell transfer) could restore the impaired immune response against cancer cells, while their efficacy influenced by any factors that affect immune surveillance, such as the microbial community of the gastrointestinal tract [159–161]. Here, CD274 is linked to cancer.