Macrophages are a type of immune system cell often bound up with malignant tumors. Weiskopf studies ways to stimulate them to kill cancer cells. Last year, he also began a parallel initiative: identifying drugs that suppress the hyperactive macrophage activity occurring in severe COVID-19. “Basic biomedical research enables us to leverage new knowledge in unanticipated—even paradoxical—but beneficial ways,” Weiskopf says. Having identified several FDA-approved drugs that appear effective at blunting macrophage activity in the laboratory, he hopes to begin preclinical trials of their effectiveness in countering the macrophage-mediated “cytokine storm” that develops in severe COVID. Longer term, he sees potential for using macrophage-suppressing drugs to treat autoimmune conditions such as multiple sclerosis and hemolytic anemia.