Has very low kinase activity in vitro and is unlikely to function as a tyrosine kinase in vivo (By similarity). Receptor for ligand WNT5A which activate downstream NFkB signaling pathway and may result in the inhibition of WNT3A-mediated signaling (By similarity). In inner ear, crucial for spiral ganglion neurons to innervate auditory hair cells (PubMed:27162350). At postnatal P0, expressed in heart, lung, liver, kidney, spleen and inner ear. At postnatal P0, expressed in heart, lung, liver, kidney, spleen and inner ear (PubMed:27162350). In the inner ear, at 14.5 dpc, detected in spiral ganglia, the cochlear epithelium and the vesitbule. At 17.5 dpc, expression increases in spiral ganglion neurons axon terminals adjacent to auditory hair cells. In the differentiating cochlear epithelium, the expression is intense in the stria vascularis. By P0, expression in the stria vascularis is weakened (PubMed:27162350). Mutant mice are severely deaf, with preserved otoacoustic emissions. They have malformed cochleae with fasciculation defects in axons of spiral ganglion neurons. Type I neurons show impaired synapses with inner hair cells and type II neurons display aberrant projections through the cochlear sensory epithelium. Belongs to the protein kinase superfamily. Tyr protein kinase family. ROR subfamily.