PDGFRB and pulmonary arterial hypertension: Many genes are functionally related to high-altitude physiology, such as angiogenesis (RGCC), pulmonary hypertension remodeling (PLA2G12A), oxygen intake (C9ORF3), neural response (GRID1 and GRIN2B), melanin synthesis (MITF, PDGFRB and PIK3R3) and heart development (FOXS1, GAA and MYLK2).