KLRD1 and hepatocellular carcinoma: Recent studies have shown that several molecules, notably, inhibitory factors, often found in the tumor microenvironment (TME), can sharply impair NK cells’ phenotype and functions [8], resulting in a decreased expression of activating NK cell receptors and an increased expression of the inhibitory receptors (like LAIR-1, which was detected previously in hepatocellular carcinoma (HCC) clinical blood samples’ T-cytotoxic cells) [9].