TGFB1 and cancer: TGF‐β1 is crucial for the development of TME, which largely promotes regulatory T‐cell infiltration, angiogenesis, epithelial‐mesenchymal transition (EMT) etc.3, 4Unexpectedly, TGF‐β1 also triggers the expression of multidrug resistance p‐glycoprotein expression in blood‐brain barrier and cancer cells.11, 12