Moreover, acetylation of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) causes sustaining the vascular proliferation in the condition of PAH through downregulation of SIRT1 HDAC (histone deacetylase) (Napoli et al., 2019). This evidence concerns the gene HDAC9 and pulmonary arterial hypertension.