Using these models, we demonstrate that to form a CD103+ CD8 T cell niche in tumors requires direct antigen presentation by cancer cells through MHC class I. Despite this direct interaction in the tumor environment, we show that CD8 T cells require initial CCR7-mediated localization to lymph nodes to subsequently form a tumor CD103+ CD8 T cell population. The gene discussed is CD8A; the disease is neoplasm.