Microarray data were subjected to the robust multichip averaging algorithm using GeneSpring GX software (Agilent Technologies, Santa Clara, CA). Analysis of variance t test and fold-change calculations were also performed using GeneSpring GX software. Probability calculations of enrichment were performed using the hypergeometric probability test (http://elegans.uky.edu/MA/progs/overlap_stats.html) to calculate the statistical significance of the overlap of gene groups.