Effect of sCD27 on WM and MC proliferation and apoptosis. Effect of sCD27 (0-50 ng/mL) on proliferation of BCWM.1 LPCs (A) and LAD2 MCs (B) as assessed by tritiated thymidine uptake, as well as on induction of apoptosis of BCWM.1 LPCs (C) and LAD2 MCs (D), and on BM LPCs (E) and MCs (F) from a representative patient with WM as assessed by APO2.7 staining. (A,B) Results denote mean plus or minus 2 SD. (C-F) The first histogram represents unstained control cells, while histograms 2 through 5 represent cells stained with APO2.7 following treatment with sCD27 at 0, 0.1, 1, 10, and 50 ng/mL.