Given that sex hormones act on many non-cardiovascular tissues, influencing systemic levels of circulating TGFβ components and hence indirectly the cardiovascular system, we will learn from studies performed in non-vascular tissues and discuss how the crosstalk between TGFβ signalling and sex hormones may be applicable to vascular biology and PAH. The gene discussed is TGFB1; the disease is pulmonary arterial hypertension.