Genes driving the colonoscope.

Recent molecular genetic studies have significantly advanced our understanding of colorectal tumorigenesis. Important genetic alterations have been characterized with practical as well as biologic implications. Presymptomatic genetic testing is now available for two major inherited colorectal cancer predisposition syndromes. Genetic markers are also emerging with potentials to provide additional diagnostic or prognostic information. New avenues to design improved therapeutic agents and preventive strategies are now available.