Thanos Halazonetis holds a Dental Degree from the University of Athens and a PhD Degree in Genetics from Harvard University. He worked at Merck, Sharp & Dohme as a Research Fellow, before joining the faculty of the Wistar Institute and the University of Pennsylvania. In 2006, he joined the University of Geneva as a Professor in the Department of Molecular Biology.
His research has always focused on cancer; after studying the p53 tumor suppressor and the responses of cells to DNA double-strand breaks, his research has focused on oncogene-induced DNA replication stress and the pathways by which cells repair collapsed DNA replication forks. He is an elected member of EMBO and of Academia Europaea.