Although TFAP2A shares 83% similarity in structure with TFAP2C, it is reported TFAP2A lacks transcriptional activity at luminal gene promoters, attributed to SUMOylation of TFAP2A in luminal breast cancer cells which blocks its ability to induce the expression of luminal genes but is crucial to maintain the basal breast cancer subtype [9]. This evidence concerns the gene TFAP2C and breast carcinoma.