PLAG1 expression in CLL and healthy donor B cells. PLAG1 mRNA expression was assessed in CLL cells (n = 11) versus healthy donor control B cells (n = 8) by RT-PCR (A). PLAG1 protein expression was detected by immunoblotting of lysates from CLL cells and healthy donor B cells. Specificity of the PLAG1-specific mAb was proven in PLAG1-transfected HeLa cells (Rec.PLAG1) and cotransfection controls with PLAG1-specific siRNA (D). Protein expression in primary CLL cells (n = 29) and healthy donor B cells (n = 22) was assessed by immunoblotting of lysates with PLAG1-specific mAb and quantified by Odyssey densitometry. Two representative experiments are shown (B-C).