In Patient 1, 3 months after the initiation of etanercept, there was near resolution of hypogammaglobulinemia (IgG 383 to 752 mg/dl, IgA 46 to 76 mg/dl, and IgM < 20 to 44 mg/dl), but the lymphopenia and lymphocyte subset enumeration remained unchanged. The gene discussed is CD79A; the disease is lymphopenia.