Recent evidence demonstrates that Six1 plays a role in cellular migration and invasion during embryogenesis [4, 17–20] and in breast cancer [21, 22] through a mechanism that may involve an EMT, which was associated with increased TGF-β receptor type I (TβRI) expression and Smad-dependent transforming growth factor-beta (TGF-β) signaling. Here, SIX1 is linked to breast carcinoma.