In the present study, our data showed that CYP27B1 was upregulated after the knockout of the oncogene EZH2, which may reduce the level of H3K27me3 in ovarian cancer cells; this finding was also consistent with previous data (Sharma et al., 2017; Camilleri et al., 2018). The gene discussed is CYP27B1; the disease is ovarian cancer.