Compared to that in healthy populations, the expression of KLRG1 is increased in T-cells in patients with solid tumors such as those of breast and colorectal cancer (CRC) [8, 26, 107, 109] and decreased in NK cells in melanoma tumor tissues in mice and in lung tumor cells in patients with lung adenocarcinoma (LUAD) [16, 22, 28, 110]. Here, KLRG1 is linked to colorectal carcinoma.