CD40LG and monoclonal gammopathy: At the clinical level, the disease is consistently heterogeneous, with a behavior ranging from indolent forms, such as IgM monoclonal gammopathy of undetermined significance (IgM-MGUS) and asymptomatic WM, to highly symptomatic disease (symptomatic WM), with evolution being highly variable as well (Oza and Rajkumar, 2015).