HRH1 and hepatocellular carcinoma: HRH1 overexpression in hepatocellular carcinoma (HCC) was shown to promote tumor metastasis by inducing matrix metalloproteinase (MMP)-2 [17], and treatment with HRH1 antagonists was reported to decrease the HCC risk in patients with hepatitis B virus (HBV), HCV, or dual infection [18].