H-Y antigen is cross-presented in vivo to both MataHari and Marilyn T cells. CFSE dilution of MataHari (A) or Marilyn (B) T cells 4 days after transfer into either H-2^bRAG.KO tumor free (top panels) or H-2^k-tumor bearing (bottom panels) mice. Histograms are gated on TCRαβ and CD8 or CD4, for MataHari or Marilyn, respectively. Cells are from the inguinal and axillary lymph nodes (the tumor-draining lymph nodes in the tumor-bearing mice). Numbers represent the percentage of TCR transgenic cells that divided more than 6 times.