KAT5 and breast cancer: To further investigate whether miR-22 affects endogenous TIP60 expression, we focused on 2 of the 12 breast cancer cell lines: MCF7, an epithelial cell line that is mildly metastatic and has low miR-22 and high TIP60 expression and MDA-MB-231 which is a mesenchymal cell line, highly metastatic and has high miR-22 and low TIP60 expression.