PAH-PASMCs exposed to TubA or ACY-775 displayed a dose-dependent increase in the amount of acetylated α-Tubulin18 without affecting the total levels of α-Tubulin and the global degree of histone H3 acetylation, thus confirming the selectively of these inhibitors for HDAC6 (Supplementary Figure S4). This evidence concerns the gene HDAC6 and pulmonary arterial hypertension.