Weibel ER, Hsia CC, Ochs M. How much is there really? Why stereology is essential in lung morphometry. J Appl Physiol 102: 459–467, 2007. First published September 14, 2006; doi:10.1152/japplphysiol.00808.2006.—Quantitative data on lung structure are essential to set up structure-function models for assessing the functional performance of the lung or to make statistically valid comparisons in e...