TGFB1 and glioma: On the other side, a study identified that baicalin can increase VEGF expression through the activation of the ERRα pathway in U251 human glioma cells and implicated the participation of macrophages in angiogenesis.29 Again, TGF‐β1 promotes VEGF secretion in bone marrow derived macrophages and in oral squamous cell carcinoma TAM was reported.30