John Griffiths was one of the leading cancer surgeons of his day, a consultant surgeon at both St Bartholomew's and the Royal Marsden. Born in Llanelli, Wales, on 31 March 1926, he was the younger brother of Evan Griffiths (see above q.v.), and the son of the town's main grocer, Edgar Griffiths, and his wife, Mary Evans. He was educated at Llanelli Grammar School, where his main and abiding loves were sport and music. A keen rugby player, he played for the Welsh Schoolboys and continued playing when he followed his older brother to Barts. After qualifying, he was house surgeon to Sir James Patterson Ross and to O S Tubbs at Hill End. He spent two years as an anatomy demonstrator under A J E Cave, before becoming registrar to Sir Clifford Naunton Morgan, during which time he carried out research into the blood supply of the colon and circulating cancer cells. This led to an Arris and Gale lecture in 1955, and an MS and a Hunterian Professorship in 1958. He won a Rockefeller scholarship to Chicago in 1958, to work under Warren Cole at the University of Illinois. On his return, he became senior registrar to the North Middlesex Hospital, and was appointed to the Royal Marsden Hospital in 1961, which he combined with an appointment to Barts in 1966. He gained a reputation as one of the leading cancer surgeons of his day, with an extensive private practice. He examined for the primary, and for the Universities of Oxford and London, as well as Sri Lanka and Ghana. He was appointed professor of physick to Gresham College, London, in 1984. John had a great interest in politics and was a lifelong member of the Liberal Party, and was courted as a potential parliamentary candidate by both Liberal and Labour parties. As a student at Cambridge he experienced conversion and he was highly respected as a Christian thinker and preacher, and was a member of the council of reference of the Christian Medical Fellowship. He retired from the NHS in 1991, and from practice altogether in 1995. He had been a keen huntsman, but had to give this up in retirement. His interest in the arts continued to develop, he revitalised the Barbican Art Club, attended opera, theatre and concerts, and found time to be chairman of the Barbican Association. He married Rosemary Quick, a Barts dietitian. He died on holiday in France on 10 April 2001, a week after he celebrated his 75th birthday and his golden wedding. He is survived by his wife, daughter, Siân (a professor of public health), four sons, Andrew, Huw, Mark and Jamie, and 12 grandchildren.