E2F1 and breast cancer: For example, 17β-estradiol (E2) induces CARM1 recruitment to the E2F1 promoter, resulting in increased H3R17me2a and transcriptional activation of E2F1 and its downstream targets (CDC25A, CCNA1, CCNE1 and CCNE2), thereby promoting ERα-positive breast cancer progression86 (Fig. 4a).