Pression and localization of proteins within specific parts of the lung (22). A relatively new technique that may be helpful is laser capture microdissection (23, 24) wherein specific areas (e.g., epithelium vs. smooth muscle vs. endothelium) or even single cells can be excised from lung sections using a laser and then analyzed for mRNA or protein (23, 24).B. Historical studiesIn the mid 19th cent