CD274 and neoplasm: In a previous study, the dual inhibition of cyclooxygenase-2 (COX-2) and EGFR by melafolone led to the downregulation of PD-L1, transforming growth factor beta (TGF-β), VEGF, and the PI3K/AKT pathway, which decreased tumor cell proliferation and enhanced the proliferation of CD8+ T cells [244].