FOXP3 and breast cancer: To determine if, in breast cancer cells, miR-155 is induced by FOXP3, the expression levels of miR-155 were monitored in FOXP3 Tet-off MCF7 (ER+, PR+, HER2-) cells without doxycycline (Dox) at 0, 24, and 48 hours [37, 38].