Since HepG2 cells were a human hepatoma cell line and exhibited defective expression of endogenous cGAS,10 we tried to establish HBV infectious cell culture model from immortalized human hepatocyte NKNT‐3 cells, which has been exhibited a nonneoplastic phenotype20 and the endogenous expression of cGAS.10 HepG2 cells have been reported to exhibit susceptibility to HBV through their expression of exogenous NTCP.11 Therefore, to establish NKNT‐3 cells exhibiting susceptibility to HBV, we first prepared NKNT‐3 cells stably expressing exogenous NTCP‐myc (designated NKNT‐3/NTCP cells; Figure 1A). Here, CGAS is linked to hepatocellular carcinoma.