Furthermore, when distribution of KIR2DS4/1D was examined among chronic hepatitis, cirrhosis and HCC diagnostic groups, KIR2DS4/1D frequencies in hepatitis, cirrhosis and HCC patients were observed to be increased in turn significantly (P trend = 0.004, determined by Spearman correlation test), and this trend is dependent on both presence of KIR2DS4 and 1D (table 2). This evidence concerns the gene KIR2DS4 and hepatitis A virus infection.