IL2RG and neoplasm: Great advances in the understanding of the roles played by myeloid cells in tumor progression have depended on the observation of their systematic progression in immunodeficient host mice, such as immunodeficient non-obese diabetic (NOD)-SCID mice and NOD/LtSz-SCID IL-2rγ−/− (NSG or NOG) mice (37, 38).