MAP2K7 and breast cancer: The involvement of MEK/MAPK kinases in B1BKR-mediated signal transduction has been described in other systems, such as proliferation induction of breast cancer cells [14], while B2BKRs reveal some pharmacological heterogeneity and the choice of PI-3K and/or MEK/MAPK by the B2BKR depends on the respective cellular context [35].