FOLR2 and breast cancer: The ability of FOLR2+ macrophages (which are also found in healthy mammary glands) to activate cytotoxic T cells in breast tumors is highly important and allows us to hypothesize that, at least in breast cancer, it is easier for cancer cells to program incoming monocytes to differentiate into tumor-supporting TAMs to reprogram resident tissue macrophages, which still retain the ability to fight against cancer.