PTK7 (Protein-tyrosine kinase 7) is a member of the receptor protein tyrosine kinases. They transduce e, Xenopus/Amphibian,tracellular signals across the cell membrane. A subgroup of these kinases lack detectable catalytic tyrosine kinase activity but retain roles in signal transduction. PTK7 is a member of this subgroup of tyrosine kinases and may function as a cell adhesion molecule. It is thought to be e, Xenopus/Amphibian,pressed in colon carcinomas but not in normal colon, therefore may be a marker for or may be involved in tumor progression. It is highly e, Xenopus/Amphibian,pressed in lung, liver,Porcineancreas, kidney,Porcinelacenta and melanocytes. Weakly e, Xenopus/Amphibian,pressed in thyroid gland, ovary, brain, heart and skeletal muscle. Also e, Xenopus/Amphibian,pressed in erythroleukemia cells, but not e, Xenopus/Amphibian,pressed in colon.