(A) Mice were given 4T1, CT26, or Renca tumors (s.c.) and sunitinib initiated for 9days. MDSC analyzed by FACS at the end of treatment. (B) Splenocytes from naïve, untreated, or sunitinib-treated tumor-bearing mice; or, from 4T1+ mice depleted for MDSC (magnetic beads), or from naïve mice with isolated MDSC added in, were stimulated with anti-CD3/28, and IFNγ detected after 72 hours by FACS intracellular staining. (C) Proliferation induced specifically in response to CD3/28-stimulation in each of the above conditions is shown. (D) Representative data from 2 experiments showing CFSE dilutions in CD4 and CD8-gated splenocytes.