Patients with ALPS-FAS, however, were found to have a slightly lower level of expression of CD127 on CD4 T-cells [median 90.7% (IQR: 90.5–92), n = 3 in HC vs. 86.4% (IQR: 78–88), n = 21 in patients with ALPS-FAS, p < 0.003] but not on CD8 T-cells [72% (IQR: 70.5−85, n = 3) in HC vs. 61 (IQR: 54–75.5%, n = 21) in patient with ALPS-FAS, p > 0.1)]. Here, CD4 is linked to autoimmune lymphoproliferative syndrome.