Researchers from the University of Malaysia report that Blastocystis cultures from symptomatic individuals report different behavior with respect to capase-like proteases. Fluorescence intensity for active capase-like proteases was significantly greater in isolates from symptomatic individuals in the 72-hour in vitro culture (p < 0.001). Treatment with metronidazole inhibited the capase activation. The full free text is available from Parasites and Vectors.