Expression of TAK1 in lymphoma cell lines. (A) Lymphoma cell lines have greater expression of TAK1 and pTAK1 compared with PBMCs from healthy donors. TRAF6, which is frequently required for TAK1 activation, and β-actin were used as controls. (B) Immunohistochemical analysis of TAK1 and pTAK1 expression in the cytospins of MCL lines demonstrating a cytoplasmic distribution pattern for pTAK1.