CD274 and neoplasm: The best candidate, TPP-1 (SGQYASYHCWCWRDPGRSGGSK), (i) bound to human PD-L1 specifically and with high affinity, (ii) reversed PD-L1-mediated inhibition of T lymphocyte activation in terms of proliferation and IFN-γ release, and (iii) delayed tumor growth in a xenograft model, with effects comparable to the FDA-approved Ab durvalumab [118].