The XL isoform of BCL11A is highly expressed in a variety of pre-GC and GC-derived B-cell malignancies. Western blotting using BCL11A/123 to detect BCL11A-XL in a panel of malignant lymphoid cell lines. Cell types, indicated at the top with individual representatives (lane numbers) are arrayed from left to right according to B-cell development status. ALL, B-cell acute lymphocytic leukemia; CLL, B-cell chronic lymphocytic leukemia; NHL, non-Hodgkin's lymphoma; SMZL, small marginal zone lymphoma; FL, follicular lymphoma; MCL, Mantle cell lymphoma; DLBCL, diffuse large B cell lymphoma; BL, Burkitt's lymphoma; MM, multiple myeloma; HL, Hodgkin's lymphoma. Expression is highest in samples representative of earlier stages of B-cell differentiation (e.g., CLL, FL). Expression is low to negative in cell lines representative of later (post-germinal-center) stages of differentiation (e.g., MM and HL). The filter was stripped and re-probed (bottom panel) with anti-β-actin as a loading control.