FIGURE 1.

Experimental design. Tissue samples were acclimated for 14 days before exposure, to recover from any damage that occurred during shipping. RNA was extracted at 1, 10, 20, 30 and 40 days (circled) for microarray analysis. Basolateral medium was collected at each medium change, which was performed every 2 or 3 days, and subjected to analyses. NTV, novel tobacco vapor product