Between 1931 and 1944 he was the director of the Department of Medicine i Medical Faculty of University of Szeged.

With start of Second World War, in 1944, he and his family were deported but was returned from Austria (eyewitness).

After the end of the Second World War, he worked as the Head of the Department of Internal Medicine.

In 1963, he retired as a university professor but he continued as the President of the Hungarian Academy of Sciences until 1970.

Along with Albert Szent-Györgyi he discovered Vitamin P and proved that chemically it belongs to the flavones.