ROR1(receptor tyrosine kinase-like orphan receptor 1), also known as neurotrophic tyrosine kinase, receptor-related 1 (NTRKR1), Tyrosine-protein kinase transmembrane receptor ROR1, is a member of thereceptor tyrosine kinase-like orphan receptor (ROR) family. NTRKR1 encodes a predicted 937-amino acid protein. A 6-kb NTRKR1 mRNA is expressed strongly in human heart, lung, and kidney, but weakly in the CNS. However, a truncated 2.4-kb mRNA lacking extracellular and transmembrane domains was strongly expressed in fetal and adult CNS and in a variety of human cancers, including those originating from CNS or PNS neuroectoderm. The protein encoded by this gene is a receptor tyrosine kinase that modulates neurite growth in the central nervous system. It is a type I membrane protein and belongs to the ROR subfamily of cell surface receptors.