CD28 and amyotrophic lateral sclerosis: We identified twelve immune traits negatively correlated with ALS risk, including leukocyte count, lymphocyte count, CD3 on effector memory CD4+ T cell, CD3 on HLA DR+ CD4+ T cell, CD3 on effector memory CD8+ T cell, CD3 on terminally differentiated CD8+ T cell, CD3 on CD28− CD8+ T cell, α-2-MRAP and C4b.