SMAD4 and rectal neoplasm: CYT-high rectal tumors on the other hand, had recurrent deletions at loci 3p21.31 (RHOA), 5q22.2 (APC), 10q26.2 (MGMT), 14q32.2 (AKT1, EIF5, YY1), 18q21.2 (SMAD4, MAPK4), and a single amplification in 7p15.3 (STK31) (Fig. 5d-f and Additional file 17: Table S8).