CD274 and melanoma: Figure 1 illustrates the mechanism of interaction between PD-L1 and CD80 in T cells. Disrupting the PD-L1/PD-1 pathway shows promise in reinvigorating tumor-specific T-cell immunity suppressed by PD-L1 expression in the tumor microenvironment. PD-L1 expression has been studied as a predictive biomarker for patients with non-small lung cancer undergoing anti-PD-1 immune checkpoint inhibitor therapy. Various cancers, including lung, melanoma, urothelial, ovarian, and colorectal cancers, exhibit PD-L1 expression with varying prevalence rates [22].