By probing the role of histidine-rich proteins unique to the malaria-causing parasite Plasmodium falciparum , a team of researchers at Washington University's Howard Hughes Medical Institute, St. Louis, has opened a route to new drugs to combat the disease [ Science , 271 , 219 (1996)]. The histidine-rich proteins, which contain as many as 51 repeating sequences of histidine-histidine-alanine, circulate in the bloodstream of people stricken with malaria. Their presence in blood is the basis for a finger-prick diagnostic test for the disease. According to the Centers for Disease Control & Prevention (CDC), Atlanta, roughly 300 million cases of the disease are diagnosed each year and between 2 million and 3 million people die from it annually. About 1,000 people in the U.S. contract malaria through travel each year, says Trenton K. Ruebush, CDC's chief of malaria epidemiology. The malaria parasite has become increasingly resistant to chloroquine, the main drug used to treat the disease, notes Ruebush. Resis...