In line with findings showing an increase in proinflammatory Th1 cells in the CSF of ALS [29] and MS patients [69], we showed that the majority of CD4 T cells in the SC of SOD1G37R mice exhibited a Th1 phenotype and expressed the activation markers CD69, CD81 and the checkpoint molecule PD1 as part of their effector function within the CNS. Here, CD4 is linked to amyotrophic lateral sclerosis.