EZH2 and breast cancer: However, in most of the solid tumors, including endometrial, PCa, lung, breast cancer and melanoma [112,113,114,115], EZH2 is most often overexpressed, leading to a variant PRC that may alter the control of the target gene’s expression level [116] (e.g., high levels of H3K27me3, associated with the overexpression of EZH2, correlate with poor prognosis in PCa and lung cancer [117,118]).