We also investigated whether BRAP knockdown or p.Arg554Leu-BRAP plasmid transfection could affect BMP signaling in which there were several disease-causing genes in PAH[5–13], however neither influenced the expression of BMPR2 or phosphorylation of SMAD1/5/8 (S3 Fig). The gene discussed is SMAD1; the disease is pulmonary arterial hypertension.