The hepatic liver infiltrating NK cells in tissues of human primary liver cancer and colorectal cancer (CRC) liver metastases were compared from the data of Easom et al. [52], their results showed that NK cells with high expression of CXCR6+CD69+ and NKG2D were widely expressed in tissues of HCC and liver colorectal metastases. The gene discussed is KLRK1; the disease is liver cancer.