The following four examined biochemical markers were shown to be associated with mortality in patients suffering from COPD: anemia (OR=2.62, 95% CI: 1.60; 4.29, p=0.01), hypoalbuminemia (OR=2.90, 95% CI: 1.56; 5.40, p=0.0008), elevated NT-proBNP (OR=7.54, 95% CI: 4.04; 14.10, p<0.00001), and elevated cardiac troponin T (OR=3.10, 95% CI: 1.11; 8.25, p=0.03). The gene discussed is NPPB; the disease is anemia.