SPN and neoplasm: Although the number of tumor-infiltrated NK 1.1+ cells was comparable in mice treated with either NK cell therapy, the percentages of matured CD11b+ CD43+ NK in both tumor-infiltrated NK cells and tumor-infiltrated CD45+ leukocytes were increased twofold by Smad3 knockout NK cell therapy compared with Smad3 wild-type NK cell therapy, while the increments were also abolished when GM-CSF was knocked down in Smad3 knockout NK cells (Fig. 7B).