PFS, and CD38 and CD138 expression by flow cytometry and immunohistochemistry in patients with Waldenström macroglobulinemia treated with daratumumab. (Ai) PFS of 13 patients with WM treated with daratumumab. (Aii) Baseline CD38 expression in B cells and plasma cells (box and whisker plots represent median and 95% confidence intervals) in WM patients who attained less than PR and who attained PR. Representative CD38 and CD138 expression by flow cytometry (B) and immunohistochemistry (C) in a patient with WM treated with daratumumab.