George Klein: 1925-2016.

George Klein, famous cancer biologist and acclaimed writer on matters of science, human responsibility, and the human condition, decorated by innumerable awards, honorary doctorates and other honors, elected member of this Academy and many other learned societies, including the Royal Swedish Academy of Sciences and the American Philosophical Society, and Member of the Nobel Assembly of Karolinska Institute from 1957 to 1993, died on December 10, 2016 at the age of 91. He will be dearly missed by pupils, colleagues, readers, and friends throughout the world, many of whom he stayed connected with until the very end of his life. In a unique way, this included people from not only diverse fields of science, but also philosophers, historians, and artists. Klein leaves behind his wife Eva (nee Fischer), herself a distinguished biologist and scientific partner from the beginning. They had a son and two daughters. Klein was born in 1925 into an assimilated Jewish family in the Hungarian-speaking part of present Eastern Slovakia, where he grew up in a well-educated and cultured environment. He moved with his mother and step-father to Budapest at the age of five. The outbreak of World War II and the German occupation of Hungary in March 1944 led to defining experiences in Klein’s life. Working as an assistant secretary at the Jewish Council in Budapest, he learned, in April 1944, of the Vrba–Wetzler Report, which was secretly communicated to the Jewish Council after Rudolf Vrba’s and Alfred Wetzler’s escape from Auschwitz and represented a firsthand account of the fate of deported Jews. Met by disbelief among his relatives and friends, the report made Klein, after having been arrested and pressed into forced labor, ultimately escape from the train station where the deportation wagons were waiting. He lived underground in Budapest until the liberation of the city by the Russian army in January 1945. Having escaped from almost certain death, Klein threw himself with all intensity into studying medicine, which had been his intention for years. He first attended the university in Szeged and then, as soon as it opened, in Budapest. Soon, however, the political developments following the country’s liberation became discomforting and Klein decided to make a second escape, this time abroad to Sweden, where he settled with his wife Eva in the summer of 1947, shortly before Hungary disappeared behind the iron curtain (1, 2). Still medical students, Klein and his wife were accepted into Torbjörn Caspersson’s laboratory at the Karolinska Institute in Stockholm, and that’s where their scientific careers really started. Eva and George Klein would work together at Karolinska until George Klein’s death. To work in Caspersson’s department was a stroke of luck. In an early attempt to combine cell morphology with cytochemistry, Caspersson tried to analyze the distribution of proteins and nucleic acids in various types and organelles of cells by UV microspectroscopy. Soon the Kleins would run experiments trying, unsuccessfully, to determine protein-nucleic acid distribution in living Ehrlich ascites tumor cells. Work in Caspersson’s laboratory also addressed the banding pattern of polytenic insect chromosomes, anticipating the development of banding techniques of mammalian chromosomes by Caspersson and Lore Zech many years later, and used by Klein and colleagues for their pioneering work on chromosomal translocations in cancerogenesis, as discussed below. Caspersson also arranged early on for Klein to spend 4 months at the Fox Chase Cancer Institute in Philadelphia, where he met geneticists like Jack Schultz and Theodore Hauschka and familiarized himself with genetic approaches and inbred strains of mice, unavailable at that time in Sweden. Apart from the science, Klein experienced the nonhierarchical structure and free spirit at Fox Chase as a personal revelation. When he returned to the Karolinska, the stage was set for the groundbreaking work on tumor immunology and George Klein. Image courtesy of Stefan Imreh (Karolinska Institutet, Stockholm).