Studies have confirmed that many proteins related to the acquired immune system, such as anti-heat shock protein- (HSP-) 70 antibodies [57], C-X-C motif chemokine 13 (CXCL13) [58], anti-vimentin antibodies [59], and some T-cell subpopulations, might be associated with worse prognosis, acute exacerbations, and pulmonary hypertension. The gene discussed is CXCL13; the disease is pulmonary arterial hypertension.