and Richard Jackson, who had discovered the RNA strand used to start haemoglobin synthesis. After 3–4 years, the team discovered at least two other chemicals acting as inhibitors. Hunt regularly spent summers working at the Marine Biological Laboratory at Woods Hole, Massachusetts, which was popular with scientists for its advanced summer courses, and in particular, with those interested in the study of mitosis. The location provided a ready supply of surf clams and sea urchins amongst the reefs and fishing docks, and it was these invertebrates that were particularly useful for the study of the synthesis of proteins in embryogenesis, as the embryos were simply generated with the application of filtered sea water, and the transparency of the embryo cells was well suited to microscopic study. Discovery of cyclins It was at Woods Hole in the Summer of 1982, using the sea urchin (Arbacia punctulata) egg as his model organism, that he discovered the cyclin molecule. Hunt was a keen cyclist and named the protein based on his observation of the cyclical changes in its levels. Cyclins are proteins that play a key role in regulating the cell-division cycle. Hunt found that cyclins begin to be synthesised after the eggs are fertilised and increase in levels during interphase, until they drop very quickly in the middle of mitosis in each cell division. He also found that cyclins are present in vertebrate cells, where they also regulate the cell cycle. He and others subsequently showed that cyclins bind and activate a family of protein kinases, now called the cyclin-dependent kinases, one of which had been identified as a crucial cell cycle regulator by Paul Nurse. The cyclin mechanism of cell division is fundamental to all living organisms (excluding bacteria) and thus the study of the process in simple organisms helps shed light on the growth of tumours in humans. Later career In 1990, he began work at Imperial Cancer Research Fund, later known as the Cancer Research UK London Research Institute, in the United Kingdom, where his work focused on understanding on what makes cell go cancerous, that is: proliferate uncontrollably, with the ordinary inhibitory signals switched off. Hunt had his own laboratory at the Clare Hall Laboratories until the end of 2010, and remains an Emeritus Group Leader at the Francis Crick Institute. He is a member of the Advisory Council for the Campaign for Science and Engineering. He has