Although there have been no reports of an association between anti-PDGFR and clinical features in SSc patients, a recent study found that agonistic antibodies induced the proliferation and migration of human pulmonary vascular smooth muscle cells in vitro [136]; this indicates that anti-PDGFR antibodies may be involved in establishing PAH in SSc, although this has not yet been investigated in vivo. The gene discussed is PDGFRB; the disease is pulmonary arterial hypertension.