CDK4 and lung adenocarcinoma: Cooperativity between MET inhibition and CDK4/6 inhibition in reducing colony-formation capability was also observed in cell lines derived from other cancer types, namely in the oestrogen/progesterone receptor-positive MCF7 human breast carcinoma-derived cells (MCF7) and in the KRAS-mutated A549 human lung adenocarcinoma-derived cells (A549) (Fig. 3e, f).