In a panel of five colon cancer cell lines, RNAi-mediated TIMELESS depletion for 72 hours ubiquitously caused an increase in γH2AX, a marker of DNA damage (Fig 5); however, the cell lines demonstrated variable levels of H2AX phosphorylation with HCT15 cells resulting in a relatively small increase. This evidence concerns the gene H2AX and colonic neoplasm.