The increase of KLRG1+ NK cells we observed in Cish-deficient mice, together with the reduction in Imm and M1 NK cells, and the increased uptake of EdU amongst all three maturation subsets suggests that CIS slows down the rate at which NK cells cycle through from the Imm stage to the M2 stage. This evidence concerns the gene KLRG1 and in situ carcinoma.