Enhancer of zeste homolog 2 (EZH2), an essential component in epigenetic polycomb repressive complex 2 (PRC2), is required for maintaining CSC properties showing enrichment of CSC, enhanced self-renewal ability and particular transcriptional pattern in multiple types of cancers including breast cancer [7], glioblastoma [8] and pancreatic ductal adenocarcinoma [9]. Here, EZH2 is linked to breast cancer.