MAPK1 and neoplasm: By controlling the stability of protein kinases (PKA and Lats/Mob1), praja2 integrates signals carried out by two evolutionary conserved transduction cascades, having a major role in cell proliferation and tumor growth.28 Large-scale proteomic analyses revealed that praja2 is a component of a macromolecular complex that includes the ERK scaffold KSR1.31 Based on this finding, we tested whether praja2 interacts with and regulates the stability KSR1.