CEACAM5 and neoplasm: Both DWI and T2* were established for tumor imaging as they yield information about impaired cell integrity or microenvironment.[10,14–16] There have been promising results published for DWI imaging for rectal cancer diagnosis[15,16]; however, there is no reliable option to predict tumor regression by single pre- or post-treatment apparent diffusion coefficient values up to now.[17] Our concept is to establish robust longitudinal assessment in order to extrapolate signal trends, as it is successfully performed with serum tumor markers (carcinoembryonic antigen, CA19-9).