In order to clarify the specific binding sites, we constructed plasmids with five separate structural domains of AIB1 with a Myc tag and full-length plasmids, respectively, and co-transfected them with Flag-PCAF plasmid in endometrial cancer cell lines, which not only proved the protein interactions but also identified the specific roles of PCAF and AIB1 in the region of amino acids 580–840 by immunoprecipitation (Figure 5B). Here, MYC is linked to endometrial cancer.