EP300 and malignant colon neoplasm: Co-immunoprecipitation using nuclear extracts from RKO, LoVo, and SW480 colon cancer cells showed that p300 was present in the immune complexes immunoprecipitated by specific antibodies against XRCC5, and XRCC5 was also present in the immune complexes immunoprecipitated by specific antibodies against p300 vice versa, as shown in Fig 5B.