PRMT1 and monoclonal gammopathy: ROC curve analysis (Fig. 1E) suggested that PRMT1 expression could differentiate MM from normal donors (AUC = 0.8658, 95% confidence interval (CI): 0.7833 to 0.9482, p < 0.0001), monoclonal gammopathy of undetermined significance (MGUS) (AUC = 0.7615, 95%CI: 0.6515 to 0.8715, p = 0.002) and smoldering multiple myeloma (SMM) (AUC = 0.7922, 95%CI: 0.6878 to 0.8967, p < 0.0001).