USP7 and breast cancer: PROTAC PU7-1, targeting FOXM1 through the involvement of USP7 (Ubiquitin Specific Peptidase 7), significantly reduces FOXM1 protein levels in breast cancer cells and inhibits cell proliferation in MDA-MB-468 (IC50 1.8 μM) and BT549 (IC50 2.8 μM) TNBC cells.