TP53 and colorectal cancer: To study whether p53 plays a role in the chromatin dislodgement of the arrested elongating RNA polymerase II (S2P RNAPII) following DNA double-strand break (DSB) induction, we monitored the profile changes of the S2P RNAPII by chromatin immunoprecipitation (ChIP) in HCT116 p53+/+ and p53-/- colorectal cancer cell lines.