TP53 and breast cancer: To see how general this conclusion might be, we carried out U3 or U8 depletion in several additional cell lines: three lung cancer cell lines (H1975, A549, DMS-53), one breast cancer cell line (BT-549), one cervical cancer cell line (HeLa), and a pair of isogenic colon carcinoma cell lines (HCT116 p53+/+ and HCT116 p53−/−).