Homodimers and heterodimers of AP-2 family transcription factors TFAP2A (AP-2 alpha), TFAP2B (AP-2 beta) and TFAP2C (AP-2 gamma) can bind to AP-2 response elements in the ERBB2 gene promoter (Bosher et al. 1996). TFAP2A forms a complex with YY1 (Ying Yang 1) transcription factor and recruits it to the ERBB2 promoter (Begon et al. 2005). Interaction of YY1 with TFAP2B and TFAP2C has not been examined but is plausible based on sequence similarity.