It was not odd that an upstate New York farmer would bring a sick Plymouth Rock hen to Peyton Rous at the Rockefeller Institute in 1909, nor that Rous would be interested in the case. Two years earlier, Hungarian veterinarian Joseph Marek had identified the costly, highly transmissible visceral leucosis of the chicken which now bears his name, and a pair of Danish researchers had identified the viral etiology of a chicken leukemia in 1908. Might the chicken hold a revelation about viral-inducing tumors in humans? Rous wondered, even as conventional medical wisdom strongly rejected that possibility.
In Rous's first line of experiments, he transplanted bits of the original hen's breast tumor to other purebred Plymouth Rocks and mixed-bred chickens, producing tumors in the purebred stock alone--which suggested an inherited susceptibility (J Exp Med, 12:696-705, 1910). Subsequently, he demonstrated transmission of malignant new growth from a cell-free filtrate, and how ...
