To determine baseline expression in the respective hepatoma cell lines Huh7 and Huh7.5 used for either the replicon system (Huh7) or the infection system (Huh7.5) expression of EGFR, ErbB2, ErbB3 and ErbB4 within both hepatoma cell lines was determined and compared to primary human hepatocytes (PHH). The gene discussed is ERBB2; the disease is infection.