HIF1A and chronic obstructive pulmonary disease: HIF-1α protein expression was also elevated in BAL macrophages isolated from smokers (6.1±2.7pg/ml, p<0.001, 95% CI [4.3, 7.8]) and COPD patients (8.2±3.4pg/ml, p<0.001, 95% CI[6.5, 10.0]) compared to non-smokers (2.3±1.5ng/ml, 95% CI[1.5, 3.0] Fig 1D).