 In 1986 he moved to California as staff physician at Scripps Clinic, and Head of the Division of Biochemistry at The Scripps Research Institute.Early in his career, while studying a vitamin B12-dependent enzyme, Babior recognized that free radicals might play an important role in biologic processes.He showed that the highly reactive oxygen derivative, superoxide was produced by white blood cell NADPH oxidase as a mechanism to kill invading bacteria.