In this study, we tested the hypothesis that enhanced AQP1 expression in PASMCs from the well‐established SuHx rat model of PAH contributes to apoptosis resistance due to reciprocal regulation of BAX and Bcl‐2, with high AQP1 levels causing an increase in Bcl‐2 and repression of BAX. This evidence concerns the gene BAX and pulmonary arterial hypertension.