FLT1 and breast cancer: VEGFA production by BC cells also plays a major role in immune evasion by stimulating recruitment to the primary tumor of immunosuppressive myeloid-derived suppressor cells, regulatory T cells, and tumor-associated macrophages; by inhibiting the recruitment and activation of cytotoxic T cells; and by inhibiting dendritic cell maturation and activation — effects that are primarily mediated via VEGFR1 (66–68).