TGFB1 and breast cancer: Hypoxic-induced exosomal delivery of TGF-β contributes to the elevation of TGF-β signaling, resulting in the regulation of human MENA alternative splicing and promoting EMT in breast cancer via the TGF-β-RBFOX2 (RNA binding Fox-1 homolog 2)-ESRP1 (epithelial splicing regulatory protein 1) axis [39].