[Summary is not available for the mouse gene. This summary is for the human ortholog.] The protein encoded by this gene is a member of the immunoglobulin/fibronectin type III repeat family. It is a component of a cell-surface receptor complex that mediates cell-cell interactions between muscle precursor cells, and promotes myogenic differentiation. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Sep 2014]