Updated project metadata. Hepatic complications of HCV infection, including fibrosis and cirrhosis are accelerated in HIV-infected individuals. Although liver biopsy remains the gold standard for staging HCV-associated liver disease, this test can result in serious complications and is subject to sampling error. These challenges have prompted a search for non-invasive methods for liver fibrosis staging. To this end, we compared serum proteome profiles at different stages of fibrosis in HIV/HCV co- and HCV mono-infected patients using SELDI-TOF MS.