Tim Hunt was, until his retirement in 2010, a principal scientist at Cancer Research UK, Clare Hall Laboratories, in South Mimms, Hertfordshire. Tim Hunt was born in 1943 and grew up in Oxford, moving to Cambridge to study Natural Sciences in 1961. He obtained his PhD (“The Synthesis of Haemoglobin”) from the Department of Biochemistry in Cambridge in 1968 and spent almost 30 years in Cambridge, working at the Department of Biochemistry, at first on the control of protein synthesis in red blood cells and from about 1983 onwards on the control of the cell cycle. He was a postdoctoral Fellow at the Albert Einstein College of Medicine in New York from 1968-70 and spent summers at the Marine Biological Laboratory, Woods Hole from 1977 until 1985, teaching laboratory courses and doing research on protein synthesis in sea urchin eggs and clam oocytes. In 1982, he chanced to discover cyclins, which turned out to be components of “Key Regulator(s) of the Cell Cycle”. This led to a share of the Nobel Prize in Physiology or Medicine in 2001, together with Lee Hartwell and Paul Nurse. Tim Hunt was chairman of the council of EMBO (European Molecular Biology Organization) from 2006 – 2010. From 2011 to 2015, he was a member of the Scientific Council of the ERC (European Research Council). Together with John Wilson, Tim has been helping to make up problems for Molecular Biology of the Cell by Alberts et al. since 1985, and The Problems Book is now in its 6th edition.