SCGB1A1 and chronic obstructive pulmonary disease: This may be of particular relevance to disease states since it has been noted that markers of cell type such as the secretory cell marker CCSP can be misleading when used for the enumeration of cell numbers in COPD patient samples (Pilette et al., 2001), in asthma (Shijubo et al., 1999), and in smokers (Shijubo et al., 1997) presumably due to the fact that CCSP has been secreted into the lumen.