ORAI1 and pulmonary arterial hypertension: In addition, changes in STIM1, STIM1L, and Orai1 have been observed in a pulmonary hypertension model of monocrotaline-induced RV-hypertrophy in which STIM1 expression was reduced but the expression of both STIM1L and Orai1 were increased and this was associated with significant changes in Ca2+ handling (Sabourin et al., 2018).