CD274 and colorectal carcinoma: In NSCLC, tumor-derived circUSP7 is synthesized and released in an exosomal manner, hindering the secretion of IFN-γ, TNF-α, granzyme-B, and perforin by CD8+ T lymphocytes or upregulating Src homologous region 2-containing protein tyrosine phosphatase 2 expression to inhibit CD8+ T cell function.95 Additionally, matrix Gla protein, a calcium-binding matrix protein secreted by CRC cells and significantly upregulated, can enhance intracellular calcium ion levels, promote NF-κB phosphorylation, activate PD-L1 expression, and contribute to CD8+ T cell depletion.96 (Fig. 4d).