The final logistic regression formula for predicting PAH in CTD-ILD patients was:logit (PPAH) = −10.31794 + 0.25012 × respiratory rate + −0.07694 × DLCO% predicted + 0.13922 × TLUS score + 1.10919 × RBC + 0.0224 × BNP. The gene discussed is NPPB; the disease is pulmonary arterial hypertension.