E2F1 and ovarian cancer: Additionally in SKOV3 sg87-13#, cell proliferation was inhibited compared with the control group, but this impairment could not be reversed by inhibitors (Figures 4E and S3F).To explore how the high expression of EZH2 caused by the EZH2-miRNA positive feedback promotes the malignant proliferation of ovarian cancer, we examined the expression of the proliferation-related molecules p21, p57, p27, p53, E2F1, cyclin d1, c-myc and RUNX3, which function downstream of EZH2 by qRT–PCR.