TP53 and colonic neoplasm: Given that APC loss of function and KRAS hyperactivation are part of the initial steps in colon cancer formation (Additional file 4: Figure S4A), we asked whether LEF1 is required for the growth of HCEC partially transformed by the expression of truncated APC, mutant KRAS (V12) or knocked down for P53, the 3 major genetic events driving colon cancer formation.