To that end, we demonstrate that human T cells in our HIS mouse models (herein referred to as SRG: human SIRPα/Rag2−/−/IL-2Rγc−/− or SRG-15: human SIRPα/Rag2−/−/IL-2Rγc−/− human IL-15) can mount a natural tumor-specific response against Raji tumor cells (an allogeneic B-cell lymphoma) that results in rejection of growing Raji tumors in SRG or SRG-15 mice. This evidence concerns the gene RAG2 and neoplasm.