The median residual IgG level at time of infection was 3.2 g/L (range 0.3–11.0), median IgA 0.3 g/L (range 0.1–4, excluding patients with IgA myeloma), and median IgM 0.2 g/L (range 0.1–1.1). The gene discussed is CD79A; the disease is infection.