Using a transplantable murine model of acute myeloid leukemia (AML) in which tumor antigen-specific CD8+ T cells undergo deletional tolerance, this study found that only the cross-presenting CD8α + CD11c + dendritic cells (DC) engulf AML-derived cellular material, and these professional antigen-presenting cells (APC) are required for antigen cross-presentation to CD8+ T cells in vitro. The gene discussed is ITGAX; the disease is acute myeloid leukemia.