Effect of AZ-TAK1 on primary lymphoma cells. (A) TAK1 and pTAK1 are abundantly expressed in primary MCL cells. Incubating the cells with 300nM of AZ-TAK1 for 24 hours inhibited TAK1 phosphorylation, down-regulated XIAP, and cleaved caspase 3. (B) TAK1 expression in lymph node sections of primary MCL, classic HL, DLBCL, and ALK (+) ALCL cases. Sections of an infiltrating ductal breast carcinoma and a reactive lymph node (LN) were used as positive and negative controls, respectively. Representative staining of negative case (blastoid type), moderately positive (+), and strongly positive (++) MCL cases are shown. (C) Summary of primary cases expressing pTAK1 by IHC (D) Primary lymphoma cells were incubated with 300nM of AZ-TAK1 for 24 hours before cell viability was determined by the use of the MTS assay. Results are the mean of 3 experiments (± SEM).