The effect of H3R antagonist 4 (0.1–100 μM) on proliferation of HEK-293 and hepatoma HepG2 cell lines was assessed and compared with the reference cytostatic drug doxorubicin (DX) and hepatotoxin carbonyl cyanide 3-chlorophenylhydrazone (CCCP) (Figure 4A,B). This evidence concerns the gene HRH3 and hepatocellular carcinoma.