Transcriptional activity of TFAP2 (AP-2) transcription factor family homo- and heterodimers in inhibited by binding of KCTD1 or KCTD15 to the AP-2 transactivation domain (Ding et al. 2009, Zarelli and Dawid 2013). Transcriptional activity of TFAP2A, TFAP2B and TFAP2C is also negatively regulated by SUMOylation mediated by UBE2I (UBC9) (Eloranta and Hurst 2002, Berlato et al. 2011, Impens et al. 2014, Bogachek et al. 2014). Binding of the tumor suppressor WWOX to TFAP2C inhibits TFAP2C translocation to the nucleus (Aqeilan et al. 2004). Transcription of the TFAP2A gene may be inhibited by CREB and E2F1 (Melnikova et al. 2010).