This study identifies the key roles of two Plasmodium asparyl proteases , Plasmepsins IX and X that are crucial for malaria parasites entry and exit from the infected host cells Remarkably, a peptidomimetic inhibitor of theses two proteases exhibits a potent preventive, therapeutic, and transmission-blocking activity against malaria through the mosquitoes. The picture is modified from Sturm and Hueussler, Med Microbiol Immunol (2007) 196:127–133 and designed by Cygny Malvar.