Prosaposin is immunolocalized to muscle and prosaptides promote myoblast fusion and attenuate loss of muscle mass after nerve injury. - Rende,M.; Brizi,E.; Donato,R.; Provenzano,C.; Bruno,R.; Mizisin,A.P.; Garrett,R.S.; Calcutt,N.A.; Campana,W.M.; O'Brien,J.S. (Muscle Nerve, 2001)