Previous work has showed that DCAMLK1 is not detectable in the blood of healthy non smoking individuals. To determine whether smoking and or pulmonary inflammation induce DCAMLK1 expression, the investigators will obtain serum samples from 20 control patients with lung disease who are seen in the Chest Clinic at the Oklahoma City VAMC. Smoking histories will be obtained for all participants and DCAMLK1 levels will be correlated with smoking status.