Chromatin immunoprecipitation (ChIP) assay verified that EZH2 inhibitors resulted in a marked reduction of H3K27me3 recruitment in Ccl2 promoter region (Fig. S5A), giving clear evidence that inhibition of EZH2 histone methyltransferase activity accounts for Ccl2 transcription induction in BC cells. Here, PRDM9 is linked to breast cancer.