Immunosurveillance of naturally occurring feline leukemia.

When compared to their housemates that subsequently developed leukemia, cats that remained healthy had five-to tenfold higher (geometric mean) humoral antibody titers to the feline oncornavirus-associated cell membrane antigen. This is compatible with the application of the immunosurveillance hypothesis to the natural development of leukemia in an outbred mammalian species.