Many host cell restriction factors that limit transcription and replication of HPV such as Sp100, miR-145, p56, Gamma-interferon-inducible protein 16 (IFI16), CCAAT/Enhancer Binding Protein Beta (C/EBPβ), p53, Epidermodysplasia verruciformis (EVERs), APOBEC, Fanconi Anemia Complementation Group D2 (FANCD2) et al. could be activated by CRISPRa to block HPV infection [168]. This evidence concerns the gene CEBPB and Fanconi anemia, complementation group S.