KIR2DS4 and hepatocellular carcinoma: When we examined the effect of the combination of activating KIR2DS4 and 1D, we found that the frequency of KIR2DS4/1D was increased in HCC patients (16.9% in non-HCC group, 27.8% in HCC group, p = 0.017, OR = 1.89, 95%CI = 1.14–3.20).