Dynamics and ontology of the transcriptional response to HDACi. Significant genes were identified by ANOVA (fold change >1.5, FDR <10 %) and clustered by SOTA. The four major clusters represent genes that were up- or down-regulated, either with or without a delay. Minor clusters, containing less than 1 % of all genes, are not shown. Each subset of genes was subject to ontological analysis by DAVID. For each significant annotation cluster (enrichment score >2) the top ontological term is shown. For each gene ontology term, count refers to the number of significant genes involved in that term, fold enrichment represents the enrichment in the significant gene list, of genes involved in that term relative to background, and the P value is a measure of the significance of that enrichment.