The contribution of the Grb2/Ras/MAP-kinase pathway to the protection by IGF-1 of oestrogen-responsive breast cancer cells from anoikis was tested with U0126 which is a non-competitive inhibitor of MEK1 and MEK2 [32, 33] that prevents activation of ERK1 and ERK2. This evidence concerns the gene MAP2K1 and breast carcinoma.