All predictors (lung disease, age > 65 years, PVR > 5 WU, BNP > 200 pg/dL, and 6MWD) had a variance inflation factor (VIF) close to 1, suggesting mild correlation between them in the multivariable Cox regression model, but not to a degree that impacts the reliability of the model. The gene discussed is NPPB; the disease is lung disorder.