To analyse the direct anti-tumour effects of rIL-21-treated Tim-3+PD-1+eYFP− NK cells, these cells were adoptively transferred into IL-2Rγ−/−Rag2−/− mice (lacking B cells, T cells and NK cells) bearing MC38 H-2Kb and H-2Db KO tumours. The gene discussed is IL2RG; the disease is neoplasm.