TBX4 was first suspected as a candidate risk gene of PAH due to the location on chromosome 17q23.1 to 23.2, where microdeletions were associated with severe neurodevelopmental delays and pulmonary hypertension (Ballif et al., 2010; Nimmakayalu et al., 2011). This evidence concerns the gene TBX4 and pulmonary arterial hypertension.