TP53 and colorectal cancer: In p53 wt HCT116 cells, an initial induction of FOXM1, TYMS, and E2F1 expression was observed followed by a decrease at later time-points; however in p53 mutant DLD1 and HT29 colorectal cancer cells these proteins remain elevated, which is consistent with previous studies demonstrating that p53 is required for the downregulation of FOXM1 acting through p21Cip125 and DNA-damage strongly up-regulated the level of FOXM1 in the absence of functional p5319,25.