Cover photograph (Copyright © 2008, American Society for Microbiology. All Rights Reserved.): Confocal micrograph showing the endoplasmic reticulum (ER) in living Entamoeba histolytica trophozoites. E. histolytica strain HM-1:IMSS trophozoites stably expressing an ER-targeted green fluorescent protein fusion protein were allowed to adhere to a glass-bottomed petri dish, covered with a thin layer of agar to restrict parasite movement, and examined using a confocal microscope. In fixed cells, the ER appeared vesicular as has been previously described (not shown). In living trophozoites, the ER-targeted fusion protein localized to a widely distributed reticular network and was absent from pseudopodia, suggesting that it was retained with a membrane-enclosed compartment. Original magnification, ×1,260. (See related article on page 1222.)