The relevance of MEK5/ERK5 signalling in cancer is increasing exponentially due to its demonstrated pro-survival, pro-proliferative and pro-angiogenic roles.5, 6, 7 Further, aberrant expression of MEK5/ERK5 was already reported in several human cancers.8, 9, 10, 11, 14, 22, 23 Our results now demonstrate the overexpression of MEK5 and ERK5 in human colon adenomas and adenocarcinomas. The gene discussed is MAP2K5; the disease is adenocarcinoma.