According to Brouet’s classification, cryoglobulinemia is categorized into three types: Type I (10-15%), which involves monoclonal immunoglobulins without rheumatoid-factor activity; Type II (65%), involving monoclonal IgM with rheumatoid-factor activity plus polyclonal IgG; and Type III (25%), characterized by polyclonal IgM and IgG with rheumatoid-factor activity [1,2]. The gene discussed is CD40LG; the disease is cryoglobulinemia.