Rous , Francis Peyton

(1879–1970) American pathologist

Rous was born in Baltimore, Maryland, and educated at Johns Hopkins University there, obtaining his MD in 1905. After working as a pathologist at the University of Michigan, he moved in 1908 to the Rockefeller Institute of Medical Research in New York, remaining there until his official retirement in 1945. Unofficially, Rous continued to work in his laboratory until his death at the age of 90.

In 1909 Rous began to investigate a particular malignant tumor of connective tissues in chickens – later to be known as Rous chicken-sarcoma. He ground up the tumor and passed it through a fine filter, extracting what would normally be accepted as a cell-free filtrate. On injection of this filtrate into other chickens, identical tumors developed. In 1911 Rous published his results in a paper with the significant title Transmission of a Malignant New Growth by means of a Cell-free Filtrate, significant because nowhere in the title (or even in the paper) does the expected term ‘virus’ occur.

It was well known by 1911 that only a virus could be present in such a filtrate, but Rous was unwilling to use the term for fear of offending his more senior colleagues. Scientists were reluctant to accept that cancer could be caused by viruses since the epidemiology of the disease was obviously different from that of such viral infections as influenza. Rous persisted with his work, however, and by the late 1930s it was widely accepted that a number of animal cancers were caused by viruses. In 1966 Rous was awarded the Nobel Prize for physiology or medicine for the discovery he had announced some 55 years earlier.

Rous also worked on the development of a number of culture techniques for both viruses and cells, techniques that have since become standard laboratory practice.