OTOR also named Otoraplin and MIAL, is a 15 kDa disulfide bonded homodimer, which is secreted via the Golgi apparatus and is a member of the MIA/OTOR family. The OTOR shares high sequence identity with the mouse (90%), chicken (80%), and bullfrog (60%) orthologs and with the related human CDRAP/MIA protein (43%). Members of this family which also includes MIA, MIA2, and TANGO share a Src homology-3 (SH3)-like domain. OTOR is mainly expressed in the cochlea of the inner-ear and appears to be involved in early chondrogenesis of the otic capsule, which is required for normal inner ear development and auditory function. It is highly homologous to MIA/cartilage-derived retinoic acidsensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells.