Progestogens may positively impact the cardiovascular system,152 by negatively regulating the hyperproliferation of ECs and SMCs.112,153,154 Progesterone induces a strong vasodilating response compared to oestradiol and testosterone in male and female rat coronary and pulmonary arteries ex vivo.114 Congruently, low progesterone levels correlate with increased risk of PAH in men.155 To date, a direct link between progestogens and TGFβ signalling (including BMPR2 regulation) in cardiovascular cells is underexplored. The gene discussed is TGFB1; the disease is pulmonary arterial hypertension.