SOD1 and lymphopenia: Taken together, our data in conjunction with a solitary report showing lymphopenia in peripheral blood of end stage G93A-SOD1 mice [60] strongly indicates the critical involvement of adaptive immune deficits in mutant SOD1-associated pathology, while early presentation of immune dysfunction prior to clinical symptoms and subsequent demise, strongly argues for the possibility that immune dysfunction and loss of adaptive immune cells reflect mechanisms other than those associated with end stage disease.