Comparison of trophozoite and schizont stages of P. falciparum. Hierarchical cluster analysis of six replicate microarray hybridizations is shown for the 854 genes that yielded at least a twofold expression difference in at least four experiments. In hybridizations 1-3, the schizont RNA was labeled with Cy3 (green signal) and trophozoite RNA was labeled with Cy5 (red signal) and in analyses 4-6, the fluorophore order was reversed. Examples of major functional gene groups enriched in either studied stage, number of corresponding ORFs and several previously characterized representatives of each group are indicated. All gene expression data are available at PlasmoDB and the DeRisi Lab website .