DKK1 and neoplasm: To further investigate whether CAFs at the tumor site suppress NK cell functions by producing DKK1, we co-cultured tdT+ CAFs isolated from orthotopic tumors in aSMA-Dkk1WT-tdT mice, together with NK cells and CTV-labeled PyMT tumor cells in the presence of IgG or mDKN01 (Fig. 6D).