Filtering for high-quality data resulted in 7,880 genes with expression values >2.5 fold over background in >70% of the microarrays. These gene expression profiles were analyzed with the SAM microarray analysis package; a two-class testing configuration was used to identify genes differentially-expressed during infection in untreated worms compared to elt-2(RNAi) worms, with a false discovery rate of 9%.