TAK-243 exhibits in vivo antiproliferative and cytotoxic activity against DLBCL tumors in mice. OCI-LY3 cells were xenografted in mice as described in Materials and methods. Mice were treated with 10 or 20 mg/kg TAK-243 or vehicle control. (A) Tumor growth was measured daily. (B-D) At the end of the experiment, mice were euthanized 2 hours after the final TAK-243 dose, and tumor cells were analyzed for apoptosis (B), proliferation (C), and expression of ER stress markers by RT-PCR (D). Tumor size was normalized to pretreatment values (represented by 0 on the y-axis). *P < .05; **P < .01.