Abstract: Human Colon Specific Polynucleotides (DNA and RNA), Polypeptides, and Antibodies, as well as methods for using and producing such polynucleotides, polypeptides, and antibodies are disclosed. More particularly, methods are disclosed for utilizing such polynucleotides, polypeptides, and antibodies to detect, diagnose, prevent, treat, and/or ameliorate cancer (particularly gastrointestinal tract cancers such as colon and pancreatic cancer). Also disclosed are compositions and methods for targeting and destroying cancer cells (particularly gastrointestinal tract cancers such as colon and pancreatic cancer) via the Colon Specific Protein and/or via the Colon Specific Protein Receptor. Moreover, methods of screening for antagonists and binding partners of the Colon Specific Protein and therapeutic uses of such antagonists and binding partners are also disclosed.