Illustration of the Turkish molecular biologist Aziz Sancar (born 1946). Sancar received his MD from Istanbul University, Turkey in 1969. After a short time working as a physician he moved to the USA to study molecular biology, receiving his PhD from The University of Texas at Dallas in 1977. He is best known for his work on DNA (deoxyribonucleic acid) repair mechanisms, especially those that repaired DNA damaged by ultraviolet (UV) light. During his PhD studies he cloned the photolyase gene from E. coli. The gene codes for the enzyme that mediates photoreactivation repair of DNA. He went on to research nucleotide excision repair in bacteria and humans, discovering the uvrABC nuclease DNA repair enzyme in E. coli and its human equivalents. He was awarded a share of the 2015 Nobel Prize in Chemistry for this work along with Tomas Lindahl and Paul Modrich.