ESR2 and atherosclerosis: In fact, many studies have shown that ERα plays a dominant role in E2-induced vasculoprotective effect [4,5,42], while using ERα and/or ERβ null mice, both ERs have shown to be necessary and sufficient for E2-mediated vascular protection [43], and recently, ERβ has indicated that it plays a crucial role in preventing early-stage atherosclerosis in ERα deficient mice [13].