Probable ligand for integrin in the brain. This is a non catalytic metalloprotease-like protein (PubMed:19692335). Involved in regulation of cell adhesion and spreading and in inhibition of cell proliferation. Neuronal receptor for LGI1. Interacts with LGI1 (PubMed:27066583). Interacts with DLG4/PSD95 (PubMed:27066583). Also binds LGI4 (By similarity). Interacts with KCNA2 and DLG2 (By similarity). Interacts (via C-terminus) with YWHAB/14-3-3 beta and YWHAZ/14-3-3 zeta but not with YWHAE/14-3-3 epsilon or YWHAH/14-3-3 eta (PubMed:12589811, PubMed:15882968). Highly expressed in the brain and in some high-grade but not low-grade gliomas. Detected slightly or not at all in other tissues. The precursor is cleaved by a furin endopeptidase. The disease is caused by variants affecting the gene represented in this entry. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.