title: A biological agent isolated by transformation.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000382:microbiology*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D017988:Gammaretrovirus / Q000302:isolation & purification* / Q000528:radiation effects; D051379:Mice; D009154:Mutation; D011830:Radiation Effects