CD4 and systemic sclerosis: The proportion of FrI cells among Treg cells (FrI/Treg) was decreased in SSc patients compared to healthy individuals, but there was no significant difference in FrI cell levels in the CD4+ compartments of patients and controls (23.19±10.60 vs 29.63±11.77 among Treg, p = 0.025; 1.87±0.94 vs 1.63±0.97 among CD4+, p = 0.320)(Figure 2A–B).