E2F1 and nonpapillary renal cell carcinoma: Studies have shown that E2F1 can not only promote cell cycle progression to the S phase but also induce DNA damage and cause cell apoptosis (25, 31, 32), which is consistent with results of our flow cytometry analysis experiments; thus, we hypothesized that PRR11 might affect the biology of ccRCC cells by targeting E2F1 activity.