High Incidence of Ependymomas Induced by BK Virus, a Human Papovavirus: Brief

tracerebrally with hlgh·tlter, purified BK virus (BKY). Tumors con· talned a T·antlgen that reacted with BKY·speclflc T·antlbody In Immunofluorescence and complement·flxatlon tests. A propor· tlon of tumor·bearlng animals had antibodies to BKY T·antlgen In their sera. BKY could be rescued from two tumor cell lines by Sendal vlrus·medlated fusion with Yero cells. A low, or lack of, on· cogenlc activity was displayed by BKY Inoculated sc, Ip, or Iv.-J Natl Cancer Inst 59: 1581-1584,1977. Establishment of the oncogenic potential of BKV, a human papovavirus (1), in experimental systems is impor· tant before BKV is considered a possible etiologic agent in human oncogenesis. Whereas in vitro transformation of ro-dent cells was readily obtained with BKV (2-.5) or its DNA (4, 6), the in vivo oncogenicity of BKV was found to be low (4,7-9)orabsent(6)