Mouse models for hereditary nonpolyposis colorectal cancer.

Hemizygous germ-line defects in mismatch repair (MMR) genes underlie hereditary nonpolyposis colorectal cancer (HNPCC). Loss of the wild-type allele results in a mutator phenotype, accelerating tumorigenesis. Tumorigenesis specifically occurs in the gastrointestinal and genitourinary tracts; the cause of this tissue specificity is elusive. To understand the etiology and tissue distribution of tumors in HNPCC, we have developed mouse models...