The other part of patients with multiple myeloma showed lower IgG, IgA, and IgM, owing to light chain type, nonsecreted type, IgD type, IgE type, etc. Most myeloma cells not only synthesize and secrete a large amount of monoclonal immunoglobulin but also have a imbalanced ratio of light and heavy chains. The gene discussed is CD40LG; the disease is plasma cell myeloma.