TP53 and cervical cancer: In HPV positive cervical cancer cells which contain wild-type p53, initial levels of p53 are significantly downregulated since E6-AP, a member of the HECT family of E3 ligases, interacts with the E6 protein found in HPV, resulting in an E6/E6-AP complex that directly targets p53 for ubiquitination and eventual proteasomal degradation [17].