In 1995 he became the fifth Sir William Dunn Professor of Biochemistry and head of the Department of Biochemistry at the University of Cambridge; he currently also holds the Chair of the School of Biological Sciences at that university. He is a fellow of Sidney Sussex College. His speciality is molecular biology and his research on identifying the chemical processes of diseases has led to the development of drugs to treat Aids, cancer, cataracts and diabetes. He is the co-founder of two drug discovery companies, Astex Technology Ltd and Biofabrika.