EZH2 and breast cancer: Clinicopathologic associations of EZH2, a transcriptional repressor that induces H3K27 tri-methylation (H3K27me3), have been drawn in many cancer types, including breast cancer, non-small cell lung cancer (NSCLC), colorectal cancer, endometrial cancer, gastric cancer, prostate cancer, ovarian cancer, and squamous cell carcinoma of the head and neck (SCCHN).