Similarly, IL-21R-deficient BXSB.B6-Yaa+/J mice presented none of the abnormal characteristics of systemic lupus erythematosus (SLE) in IL-21R-competent Yaa mice, including hypergammaglobulinemia, auto-antibody production and reduced frequencies of marginal zone B cells [45]. The gene discussed is IL21R; the disease is systemic lupus erythematosus.