Abstract
Infection with Herpes simplex viruses (HSV) induces amplification of SV40 sequences in SV40‐transformed Chinese hamster embryo cells (CO631). This is shown by in situ hybridization of the infected cells with cloned 32P‐labelled SV40 DNA. The HSV‐mediated synthesis of SV40 DNA is more pronounced than after treatment with chemical carcinogens. This initiator‐like effect of HSV may, in concert with the previously reported mutagenic activity of this virus (Schlehofer and zur Hausen, 1982), point to a possible mechanism of HSV infection in human genital cancer.