Natural Killer (NK) cells play a key role in the immune responses against infection and cancer as powerful cytotoxic effector cells and regulators of both innate and adaptive immunity [1,2]. Therefore, defects in NK cell functions are important mechanisms for immune evasion of malignant cells [3]. For instance, the ability of tumor cells and tumor-associated stromal/infiltrating cells to inhibit NK cell activity, which results in preventing NK cells from recognizing and killing tumor cells, has been reported for melanoma, neuroblastoma, gastrointestinal sarcoma, hepatocellular cancer (HCC), pancreatic cancer, colorectal carcinoma and other types of cancer [4][5][6][7][8][9]. A potential loss of NK cell numbers and function at preneoplastic stages of tumorigenesis as a possible mechanism for cancer induction and progression has been also recently proposed [5,10]. However, molecular mechanisms regulating NK cell dysfunction and exhaustion in cancer are largely unclear.Furthermore, the link between NK cell deficiency and cancer risk has been also suggested. For instance, the abnormal NK cells and their functional impairment in patients with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, which contribute to the progression of HCC have been documented [11]. Moreover, comparative mRNA gene expression profiling by wholehuman-genome microarrays combined with phenotypic and functional characterization of circulating NK cells from patients with HCV-related liver cirrhosis and HCC identified energy metabolism and cell motility defects of NK cells as main mechanisms responsible for functional NK cell damage in patients with cancer [12]. Published analysis of the 'omic' data (i.e., tumor RNA-seq and wholeexome sequences of germline genomes) representing 13 common types of cancer showed that people with inherited