The last two years have seen a renaissance of monoclonal antibodies for the treatment of disease. Of the eight antibodies currently approved for human therapy, two are for the treatment of cancer. In large part, the revival of antibodies has been driven by technology developments geared toward making antibodies less likely to elicit an anti-antibody response in humans. The development of transgenic mice, XenoMouse animals, capable of making fully human antibodies offers new opportunities for generating antibodies of therapeutic quality. Recently, this technology has been applied to the generation of a fully human antibody to the epidermal growth factor receptor. A description of the development of this antibody serves to illustrate the power and ease of use of XenoMouse technology.