PSIP1 and lung cancer: This effect was not limited to HPV-positive cells and was not linked to the p53 mutational status since LEDGF repression also resulted in a reduction of the colony formation capacity in HPV-negative C33A cervical carcinoma (mutant p53), H1299 lung cancer (p53 null) and HCT-116 colon carcinoma (wildtype p53) cells (Fig. 5B).