EZH2 levels have been demonstrated to be increased in CSCs in various malignant tumors, such as melanoma cancer [17], breast cancer [37, 38], ovarian cancer [16, 39], pancreatic cancer [37], skin cancer [40], colorectal cancer [18] and leukemia [41, 42] (Table 1). The gene discussed is EZH2; the disease is ovarian carcinoma.