ELQs were synthesized as previously described and below, identified by proton nuclear magnetic resonance (1H-NMR), and determined to be >95% pure by reversed-phase high-performance liquid chromatography (HPLC). Atovaquone was obtained from Sigma-Aldrich. Human foreskin fibroblast cells were obtained from the American Type Culture Collection (ATCC). The Type I T. gondii RH strain expressing luciferase and green fluorescence protein (gfp) were kindly provided by Vern Carruthers. The Type I T. gondii RH strain expressing gfp and β-galactosidase was kindly provided by Marilyn Parsons.