Control Lung Tissues: The Lung Tissue Research Consortium obtains surgical waste tissues from individuals undergoing lung resection or biopsy for clinical indications. The average age of individuals undergoing surgical resection in the LTRC repository is approximately 60 years. As such, the LTRC does not provide access to completely normal lung tissues. The investigator should be aware of this when requesting tissues from the LTRC repository. Appropriate controls for most studies of COPD would consist of peripheral lung tissues resected at time of nodule resection from patients with normal lung function testing parameters. However, such tissues may have some microscopic evidence of minimal centrilobular emphysema or respiratory bronchiolitis. These finding would be reviewed and scored as minimal by the LTRC lung pathologist. Appropriate controls for interstitial lung disease could also include similar tissues from patients undergoing nodule resection. Alternatively, investigators might evaluate tissue changes across patients with increasing severity of physiologic impairment related to their underlying disease (either COPD or IPF), contrasting changes in those with mild disease to those with more severe impairment.