Project Abstract While primary human airway epithelial cells (hAECs) have seen increasing use as models for in vitro toxicology screening, there remain severe drawbacks to their broad deployment. The limitations involve: (1) the very limited expansion potential of primary hAECs in culture results in small manufacturing lot sizes and high product costs; (2) the inability of propagated AECs to form fully differentiated, pseudostratified 3D tissue after only 4 to 5 passages in culture, thereby further exacerbating supply and cost issues; and (3) the issues of data variances due to lack of a systematic approach to donor variability and their genetic diversity. Taken together, these drawbacks result in small lot sizes of expanded cells from each donor and very expensive 3D tissue models, making it very challenging to provide or perform cost-effective, standardized in vitro toxicant screening. Propagenix has published on the ability of our EpiX™ cell culture technology to significantly enable the bioproduction of primary human airway epithelial cells possessing genomic stability and differentiative functionality over extended culture propagation. This program seeks to utilize this capability to build a human airway epithelial cell biobank that is intentional about incorporating genetic diversity and is accompanied by a preliminary dataset demonstrating parameters of toxicant response. Of particular importance will be information on toxicant response within specific subsets of airway epithelial cells and the future use of this information to create reporter cell models to decrease commercial barriers for in vitro toxicant screening.