MYD88 and Waldenstrom macroglobulinemia: Additionally, the varying frequency of the L265P mutation in different B cell malignancies has been puzzling: Although the MyD88 L265P mutation may be found in up to 90% of Waldenström’s Macroglobulinemia patients (12), in diffuse large B cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL) only 30 or 4% of patients carry this or other known gain-of-function MYD88 mutations, depending on subtype (7, 13).