WM is a rare lymphoplasmacytic lymphoma with monoclonal IgM paraprotein.4 Many patients are asymptomatic, and among those with symptoms, the presentation is nonspecific, with weakness, anorexia, and weight loss.5 Physical examination may reveal signs of anemia, peripheral neuropathy, hepatosplenomegaly, and lymphadenopathy. The gene discussed is CD40LG; the disease is anemia (phenotype).