The Hepatitis B Research Network (HBRN) was established in 2008 after solicitation of applications through RFA DK 07-011 . Under a cooperative agreement and sponsorship by the NIDDK, HBRN was charged with promoting translational research on hepatitis B focusing on elucidation of the pathogenesis and natural history and developing means of treatment and control. Currently, HBRN consists of 23 clinical sites under 14 individual UO 1 grants, an immunology center and a data coordination center. In order to synergize the Federal Government scientific resources towards the common goal of promoting translational research on chronic hepatitis B, the NIDDK and the CDC/NCHHSTP/DVH mutually agree to establish this relationship that will unite the hepatitis B clinical investigative expertise of the HBRN with the hepatitis B molecular diagnostics expertise of the CDC/NCHHSTP/DVH. HBRN is currently enrolling three clinical studies in adults and two in children with chronic hepatitis B that will collect and store blood specimens in the NIDDK Central Repositories. Virologic assays performed on these stored blood specimens will provide valuable data for the conduct and analysis of the clinical studies as well as provide the CDC with data regarding prevalence of viral mutations. The CDC/NCHHSTP/DVH has recently validated state of the art techniques for virologic assays for viral hepatitis B in blood specimens that would compliment the HBRN clinical studies.