CUL2 and cervical cancer: Taken our results together, we delineate a feedback regulatory loop involving CUL2, E2F1, and miR-424 in HPV16 positive cervical cancer cells, where overexpressed CUL2 promotes E2F1 expression, elevated expressed E2F1 suppresses miR-424 in turn, reduced expressed miR-424 thus abates the inhibition to CUL2, and consequently results in persistent CUL2 overexpression.