MUC6 and animal viral hepatitis: Among the proteins encoded by these genes, ubiquitin carboxyl-terminal hydrolase 6 (USP6) regulates plasma membrane localization of ADP-ribosylation factor 6 (ARF6) (Martinu et al., 2004), while mucin 6, oligomeric mucus/gel-forming (MUC6) is involved in reactive biliary epithelium in viral hepatitis (Sasaki et al., 1998).