The present invention relates to methods of treating virus-induced cancer with the polypeptides that are capable of killing cells. The polypeptide comprises a targeting agent covalently attached to a channel-forming moiety. In a preferred embodiment, the channel-forming moiety comprises a colicin and the targeting agent is a reconstructed antibody mimetic derived from monoclonal antibody variants against Epstein-Barr virus gp350/220.
