FOXP3 and breast cancer: Clinical development of strategies to target FOXP3 Tregs is underway36 with promising data on the reprogramming of Tregs through CD25 targeting emerging.37 Our data demonstrates that patients with FOXP3 positive iTILs have a poorer breast cancer-specific survival than those without FOXP3 positive iTILs, and as such, almost half of MBC patients may benefit from anti-FOXP3 therapies (55% of all MBC; a third of mixed MBC, three quarters of squamous MBC and half of spindle MBC).