TGFB1 and breast cancer: Since TGFβ is a crucial regulator of EMT, we then tested TGFβ signaling by qRT-PCR analysis of a panel of genes that are involved in driving breast cancer metastasis to the bone or lung [43, 44] in the presence or absence of TGFβ1 (Fig. 5D–G; Fig. S6D–G).