The impact on YTHDF1 knockdown on the malignancy of breast cancer cells was further quantitatively examined by flow cytometry with Annexin V/PI staining, of which the results demonstrated YTHDF1 knockdown caused pronounced apoptosis in MDA-MB-231 and MCF7 with an apoptotic cell population of 29.98 and 28.11%, respectively (Fig. 2G). This evidence concerns the gene YTHDF1 and breast cancer.