U3-1287/AMG888 in combination with radiation can delay the growth of HNSCC and NSCLC xenograft tumors. SCC6, SCC1483, and H226 xenografts were established as described in Materials and Methods. Mice were treated with vehicle control, single dose or fractionated dosing of radiation, U3-1287/AMG888 (at doses indicated in figure), or U3-1287/AMG888 in combination with radiation. Tumor volumes were presented as the mean tumor size±SE. *, P≤0.05.