Could the extracellular matrix at the NMJ in muscle be using CD44 in TSCs to stimulate IGF-1 production, a trophic factor which, when exogenously administered, is known to promote NMJ stability and improve the ALS phenotype (Kaspar et al., 2003; Dobrowolny et al., 2005)? The gene discussed is CD44; the disease is amyotrophic lateral sclerosis.