Treatment of patients with moderately to severely active SLE with epratuzumab led to reductions in the levels of CD22, with the number of B cells in the peripheral blood decreasing by ∼30–40% and IgM levels reducing by 20%. However, treatment with epratuzumab in conjunction with standard therapy did not improve efficacy outcomes at week 48 compared to treatment with placebo in conjunction with standard treatment. The gene discussed is CD22; the disease is systemic lupus erythematosus.