Professor Dame Jean Thomas is Professor Emeritus of Macromolecular Biochemistry at the University of Cambridge and former Master of St Catharine’s College. Her research has contributed to our understanding of chromatin (the complex of proteins and DNA that constitutes chromosomes) and its role in the repression and activation of genes. Professor Dame Jean Thomas was born in Treboeth, attended Llwyn-y-Bryn High School and was awarded a State Scholarship to continue her education at Swansea University, where she gained her BSc and PhD in Chemistry. Professor Thomas is a Fellow of the Royal Society, the Academy of Medical Sciences and the Learned Society of Wales, and an elected Member of the European Molecular Biology Organisation and of the Academia Europaea. She has served on many national scientific bodies including Research Councils and the Wellcome Trust (as a Governor), and was a Trustee of the British Museum for 10 years; she also served as Biological Secretary and Vice-President of the Royal Society, 2008-2013. She is currently President of the Royal Society of Biology (until May 2018), and a Trustee of the Wolfson Foundation. She has served as a Deputy Vice-Chancellor in the University of Cambridge.