ERK5 has been associated with angiogenesis, migration and tumour metastasis.13, 14, 37 We demonstrated that MEK5/ERK5 activation in vitro significantly contributed to CC cell migration, and that orthotopically implanted CC cells with constitutive MEK5/ERK5 activation develop tumours with increased invasive and metastatic potential (to regional lymphnodes). This evidence concerns the gene MAP2K5 and neoplasm.