LRFN3 is a 628 amino acid single-pass type I membrane protein that belongs to the LRFN family. Containing seven LRR (leucine-rich) repeats, LRFN3 also contains one fibronectin type-III domain, one Ig-like (immunoglobulin-like) domain, one LRRCT domain and one LRRNT domain. As a cell adhesion molecule that mediates homophilic cell-cell adhesion in a Ca2+-independent manner, LRFN3 promotes neurite outgrowth in hippocampal neurons. LRFN3 forms homomeric complexes across cell junctions (between adjacent cells), and can form heteromeric complexes with LRFN1, LRFN2, LRFN4 and LRFN5. The gene that encodes LRFN3 consists of more than 8,000 bases and maps to human chromosome 19q13.12.