EZH2 and cancer: EZH2 has been known to be significantly overexpressed in drug-resistant cancer cells of multiple myeloma, leukemia, breast, colorectal (CRC), prostate and ovarian tumours (Li et al., 2017; Li Q. et al., 2019; Li X. et al., 2021; Rastgoo et al., 2018; Wen et al., 2021; Yang et al., 2021).