CD4 and autoimmune lymphoproliferative syndrome: Moreover, in patients with ALPS-FAS, we found a higher level of expression of Ki67 in CD4, CD8, and DNT-cells compared to healthy individuals (median 6.5, 6, 44%, in CD4, CD8, and DNT of ALPS-FAS patients vs. 1.8, 2.4, 1.7% in CD4, CD8, and DNT of HC, p < 0.0001, p = 0.001, p < 0.0001, respectively) (Figure 3B).