To gain a better understanding of the role that RFX1 plays in Th17 cell differentiation, we measured the mRNA and protein expression levels of RFX1 and IL-17A in CD4+ T cells from a new cohort of SLE patients, including 23 active patients and 8 inactive patients, and 14 healthy controls. The gene discussed is RFX1; the disease is systemic lupus erythematosus.