Upregulation of STIM2 in PAH appears to be unique amongst ER and SR calcium sensors, as STIM1 levels are unchanged in IPAH, although the expression of ORAI1, TRPC1, and the anti-apoptotic protein Bcl-2 are also increased (Song et al., 2018). Here, STIM2 is linked to idiopathic pulmonary arterial hypertension.