The reactivity of anti-Sm/RNP B, -U1-C RNP-, -RNP 68-, and -RNP A-antibodies of the IgE type did not differ between patients with SLE and MCTD but was significantly higher in these patients than in patients with other CTD (Figure 2B). The gene discussed is IGHE; the disease is systemic lupus erythematosus.