IRF4 and monoclonal gammopathy: Our work has therapeutic implications derived from the observation that both c-Myc and IRF4 expression levels steadily increase over the course of MM disease progression from monoclonal gammopathy of undetermined significance to SMM, then newly diagnosed MM, and finally relapsed/refractory MM (Figure 1a), suggesting that the upregulation of this axis contributes to the pathogenesis of the disease.