Cleavage occurs at Cys 38 and was observed in different experimental systems, including heterologous expression, the replicon and HCVcc systems, as well as in liver biopsies from patients with chronic hepatitis C. NS3-4A from different HCV genotypes as well as a range of hepacivirus species efficiently cleaved OCIAD1. This evidence concerns the gene OCIAD1 and chronic hepatitis C virus infection.