For example, circRHOT1 aggravates hepatocellular carcinoma progression by recruiting histone acetyltransferase KAT5 (TIP60) to NR2F6, while circ-Foxo3 promotes the occurrence of breast cancer by acting as a protein scaffold and binging to E3 ubiquitin-protein ligase MDM2 and p53 [14]. Here, KAT5 is linked to breast cancer.