Fold change RNA of NHBE cells for IL-8 (A), IL-6 (B), HOX1 (C), and COX2 (D) following exposure to fractions of Chapel Hill ambient air pollution particle. Significant increases in RNA were observed after exposure of submerged cells to the particles fractions. However, no increased RNA was observed following exposure of NHBE cells grown at ALI to the same particle. Data was statistically analyzed using a one way ANOVA only; no effect of either fraction or mass was evaluated. *Significant increase relative to RNA in unexposed NHBE cells.