CD4 and systemic lupus erythematosus: The induction of pSTAT3 by IL-6 was similar in SLE (23.9% ± 8.8%) and in HC (24.1% ± 5.2%) both in CD4+ T cells (Figures 3A, B) and in CD8+ T cells (Figures 3C, D, SLE: 20.9% ± 9.1%; HC: 15.9% ± 4.7%).