Dr. Goldberg does basic research on the biology of malaria and identification of drug targets. Parasites have evolved many clever ways to infect their hosts and develop within them. Researching these processes at a molecular level should lead to treatment or prevention of parasitic infections that afflict most of humanity. Intraerythrocytic malaria parasites are fascinating creatures. They have evolved many clever strategies for survival inside their host cell. Most of these adaptations are still biological mysteries. Indeed, nearly half of the Plasmodium proteome comprises proteins of unknown function. Some are species or phylum specific; others have orthologs spread widely through phylogeny. We are interested in defining the roles of such proteins, with a special focus on proteases of unknown function. We use a combination of genetic and biochemical approaches to elucidate biological roles. To help us with this analysis, we have developed a regulated protein knockdown system for the study of essential proteins. This has allowed us to define a role for Plasmodium calpain in nucleolar control of cell cycle progression and a role for the aspartic protease plasmepsin V in export of parasite proteins to the host erythrocyte.