Researchers were surprised to discover that mice that lack a molecule found in a type of white blood cell had a significantly higher survival rate from malaria than those in which the molecule is present. One-quarter of mice in which the alpha D gene was knocked out survived a severe form of malaria, compared with zero survivors in a group that had functioning alpha D genes. The study confirms the role of alpha D in the body’s immune response to infection, but also indicates the molecule can cause uncontrolled inflammation that makes malaria, and possibly other systemic infections, even more deadly.