TGFB1 and neoplasm: They activate TLR2 on macrophages, increasing the expression of PD-L1 through metabolic reprogramming and the NF-kB transcription factor, utilizing HIF-1a/GLUT-1.156 During hypoxic conditions, LCEVS carry elevated transforming growth factor (TGF)-β, EGFR, and miR-23a, creating an immunosuppressive tumor-associated macrophage (TAM) population.