MAPK3 and cancer: The phosphorylation allows the binding of ERK1/2 to importin7 (IMP7) that escorts ERK1/2 to the nucleus via the nuclear pores. Importantly, a peptide (EPE) that interferes with ERK1/2-IMP7 interaction prevents nuclear ERK1/2 translocation and thereby inhibits proliferation of ERK-addicted cancer cells (Plotnikov et al., 2015).