KLRK1 and colorectal cancer: In both lung and colorectal cancer patients, elevated plasma TGFβ1 levels correlated with decreased NKG2D expression on freshly-isolated NK cells, and downregulation of NKG2D on NK cells that were derived from healthy donors and subsequently cultured with plasma from cancer patients could be prevented by the addition of neutralizing anti-TGFβ1 monoclonal antibodies to the ex vivo cultures [136].