CD40LG and neoplasm: LPL is an extremely rare neoplasm, with an annual incidence of 3 to 4 cases per million people.[1–4] The abnormal cells seen in patients with LPL have features of lymphocytes and plasma cells, and produce large amounts of abnormal antibodies called “paraproteins”.[1,4] In most cases of LPL, IgM is the paraprotein.