Many cancer researchers work with mice, and nearly as many worry about the relevance of mouse models to human cancers. Some researchers are passionate about transgenic mice, some adore athymic (nude) mice, and some prefer NOD/SCID strains.
Daniel Engber, writing in the online magazine Slate, has a wonderful 3-part series about mouse models of human disease (see here for the first article in the series). While not entirely directed at cancer research, it provides a fascinating mix of history and biology, explaining the dominance of mouse research in biologic studies, and the very real limitations imposed by the models. Highly recommended both for mouse researchers and for those with a more general interest in the research enterprise.