Overexpression of HIF-1α resulted in a significant increase (~50%, 1.8-fold) in lung surface tumor number in age and sex-matched CC-LR mice treated with the same amount and duration of doxycycline (47 ± 3 in CC-LR 87 ± 4 in CC-LR/HIF-1α Tg) (Figure 5A, 5B), which is less than the promoting effect of NTHi-induced COPD-type airway inflammation in the CC-LR model (~3.2-fold) as we have previously shown [22]. Here, HIF1A is linked to chronic obstructive pulmonary disease.