In pancreatic cancer, CAFs down regulate NKp30, NKp44, NKG2D, perforin and granzyme B expressed on NK cells by secreting prostaglandin E2 (PGE2), IDO and TGF-β, thereby decreasing NK cell cytotoxic activity (41, 42). Here, KLRK1 is linked to familial pancreatic carcinoma.