Furthermore, we found that p300 enhanced RP1 promoter activity in a dose-dependent manner withKLF5 in HEK-293T cells (Fig. S3D).Meanwhile, C646 evidently reduced RP1 inMDA-MB-231 and BT549 cells (Fig. 6g), andoverexpressing p300 in MCF-7 and SKBR3 cells accelerated RP1 expression (Fig. 6g).Moreover, we restored p300 in MDA-MB-231 and BT549 cells while knocking down KLF5,and found that p300 had no effect on RP1expression in breast cancer cells without KLF5 (Fig. S3E). Here, EP300 is linked to breast carcinoma.