Shope papilloma virus

The Shope papilloma virus (SPV), also known as cottontail rabbit papilloma virus (CRPV) or Kappapapillomavirus 2, is a papillomavirus which infects certain leporids, causing keratinous carcinomas resembling horns, typically on or near the animal's head. The carcinomas can metastasize or become large enough to interfere with the host's ability to eat, causing starvation. Richard E. Shope investigated the horns and discovered the virus in 1933, an important breakthrough in the study of oncoviruses. The virus was originally discovered in cottontail rabbits in the Midwestern U.S. but can also infect brush rabbits, black-tailed jackrabbits, snowshoe hares, European rabbits, and domestic rabbits.