ICOS and Autoimmunity: Specifically, the NOD.ICOS-/- and NOD.ICOSL-/- mice show neuromuscular autoimmunity characterized by hind leg paralysis and immune infiltration of T cells, macrophages and granulocytes in the peripheral and central nervous system (PNS, CNS), including peripheral nerves, sensory ganglia, muscles, brain, and spinal cord (91).