Stimulation of TLR3 on host hematopoietic APCs enhances GVT response. BMT and tumor induction were performed in [WT-B6→B6Ly5.2] and [Tlr3^−/−B6→B6Ly5.2] animals as described in “Materials and methods.” The recipient animals received TLR3 stimulant polyI:C or the diluent control and were analyzed for GVHD and tumor-free survival. (A) Tumor mortality data for [WT-B6→B6Ly5.2] and [Tlr3^−/−B6→B6Ly5.2] animals with 2 × 10⁴ MBL-2 cells (n = 5 to 14 per group, pooled from 2 experiments). (B) Representative photos from bioluminescence study at day 21 after allo-BMT.