PDE4B and asthma: Of the 161 differentially regulated genes identified by our expression array, we determined that the 241 SNPs within the 24 genes with the highest FST values (FST≥0.1; including SNPs within the final six genes selected - KIF3A, ADCY2, DNAH5, PDE4B, PLAU, SPRR2B) were significantly more likely (p = 0.0008, Fisher's Exact Test; 6% of SNPs reached p≤0.05) to be associated with asthma than the 190 SNPs in the 24 genes with the lowest FST values (FST = 0; 0.5% of SNPs reached p≤0.05).