title: Feline leukemia: a naturally occurring cancer of infectious origin.
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000276:immunology / Q000382:microbiology* / Q000635:transmission; D002415:Cats; D004781:Environmental Exposure; D004812:Epidemiologic Methods; D006801:Humans; D007938:Leukemia / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D005256:Leukemia Virus, Feline / Q000472:pathogenicity