KAT5 and breast carcinoma: Mechanistically, we showed that circACTN4 could upregulate the expression of MYC and that MYC might interact with TIP60 histone acetyltransferase to increase the recruitment of TIP60 to MYC target genes and histone H4 acetylation (AcH4), thus promoting the progression of the breast cancer cell cycle and tumorigenesis.