Microarray profiling of OSCs identifies mechanistic groups. (A) Microarray analysis of changes in mRNA abundance induced by 8 OSCs and two control compounds identifies that some compounds induce significantly greater alterations than others. (B) These profiles of changes in mRNA abundances can be used to clusters the compounds using a divisive hierarchical algorithm (colour bars represent fold-change relative to acetone control). (C) Mapping altered mRNA profiles to functional groups allows clustering of compounds based on their functional profiles (colour bars represent -log10|P|). (D) To assess the mechanistic underpinnings of altered mRNA abundance profiles we performed transcription factor binding site analysis, and clustered compounds into mechanistic groups (colour bars represent -log10|P|, labels indicate difference TFBS IDs). Intriguingly, the mRNA abundance, GO functional, and TFBS mechanistic results allow clustering of the data into similar, but non-identical groups.