Technologically advanced cancer modeling in mice.

Multiple approaches now exist for the generation of genetically engineered murine cancer models. These new models utilize latent, conditional and inducible alleles to better mimic the in vivo setting in which sporadic human cancers occur. The murine tumor models are beginning to reveal mysteries of tumorigenesis, such as the role of the tumor microenvironment and the dependence of tumors on continuous oncogenic stimulation.