However, these experiments are beyond the current scope of our study and whilst they have not been performed in PAH similar experiments have shown that over-expression of miR-1-5p reverses insulin-like growth factor-1 (IGF1) induced hypertrophy in vitro [26,27] and that adenoviral delivery of miR-1 to the myocardium has been shown to reverse overload induced LV hypertrophy [28]. This evidence concerns the gene IGF1 and pulmonary arterial hypertension.