I completed my medical studies at the Karolinska Institute in Stockholm but have always been devoted to basic research. My longstanding interest is to understand fundamental DNA repair mechanisms in the fields of cancer therapy, inherited human genetic disorders and ancient DNA. I initially measured DNA decay, including rates of base loss and cytosine deamination. I have discovered several important DNA repair proteins and determined their mechanisms of action. The discovery of uracil-DNA glycosylase defined a new category of repair enzymes with each specialized for different types of DNA damage. The base excision repair pathway was first reconstituted with human proteins in my group. Cell-free analysis for mammalian nucleotide excision repair of DNA was also developed in my laboratory. I found multiple distinct DNA ligases in mammalian cells, and led the first genetic and biochemical work on DNA ligases I, III and IV. I discovered the mammalian exonucleases DNase III (TREX1) and IV (FEN1). Interestingly, expression of TREX1 was altered in some human autoimmune diseases. I also showed that the mutagenic DNA adduct O 6 -methylguanine (O 6 mG) is repaired without removing the guanine from DNA, identifying a surprising mechanism by which the methyl group is transferred to a residue in the repair protein itself. A further novel process of DNA repair discovered by my research group is the action of AlkB as an iron-dependent enzyme carrying out oxidative demethylation.

Dr. Tomas Lindahl completed medical studies at the Karolinska Institute in Stockholm but has always been devoted to research. He worked on nucleic acid biochemistry with Jacques Fresco at Princeton and Gerald Edelman at Rockefeller University, and joined the faculty of the Karolinska Institute in 1969. He became Professor at the University of Gothenburg in 1978. In 1981 he was appointed Head of the Mutagenesis Laboratory at the ICRF Mill Hill Laboratories in London. From 1984 to 2006, he was Director of the Clare Hall Laboratories at ICRF and Cancer Research UK, also serving as Deputy Director of Research. Dr. Lindahl’s contributions to understanding DNA repair are fundamental and have long-lasting impact in the fields of cancer therapy, inherited human genetic disorders and ancient DNA. Beyond his own outstanding scientific achievements, his stewardship established Clare Hall Laboratories as an internationally-renowned center of research into DNA processing. The success of colleagues working together with him is a measure of his insight, support and leadership. Amongst many prestigious honours, Dr. Lindahl is a member of EMBO, a fellow of the Royal Swedish Academy of Sciences and the Royal Society. He delivered the Royal Society Croonian Lecture in 1996. Dr. Lindahl received a Royal Medal in 2007 and the prestigious Copley Medal of the Royal Society in 2010.