In rodent models of ALS, neuromuscular junction destruction and distal axonopathy precede motor neuron loss28; the early accumulation of macrophages expressing CD11b and CD68 in axons29 and of other immunologic factors originating from the muscle may play an active role in motor neuron degeneration by inhibition of neurite outgrowth. The gene discussed is CD68; the disease is amyotrophic lateral sclerosis.