TBX4 and pulmonary arterial hypertension: Other reported PAH‐associated genes includes activin A receptor like type 1 (ACVRL1), endoglin (ENG), SMAD family 1,4, 9, caveolin 1 (CAV1), bone morphogenetic protein receptor type 1b (BMPR1B), potassium voltage‐gated channel subfamily a member 5 (KCNA5), potassium channel subfamily K member 3 (KCNK3), T‐box transcription factor 4 (TBX4), DNA topoisomerase 2‐binding protein 1 (TOPBP1), growth differentiation factor 2 (GDF2) and eukaryotic translation initiation factor 2‐alpha kinase 4 (EIF2AK4) at a lower frequency (Machado, 2012; Soubrier et al., 2013).