CD4 and systemic lupus erythematosus: Accordingly, the expression levels of IL-15/IL-15RA (FC 1.4/1.2 in the CD4+ T cells, FC 1.4/1.4 in the CD16− monocytes and FC 1.5/1.8 in the CD16+ monocytes) and IL2RG (FC 2.8 in the CD4+ T cells, FC 2.9 in the CD16− monocytes and FC 1.9 in the CD16+ monocytes) were found to be upregulated in the SLE patients (Table S4).