Xenotropic murine leukemia virus-related virus

Xenotropic murine leukemia virus-related virus (XMRV) is "a laboratory-derived mouse virus that was generated through recombination between two endogenous murine retroviruses during propagation of a prostate cancer xenograft in the mid-1990’s." The chimeric virus was first described in 2006 as an apparently novel retrovirus and potential human pathogen. Initial reports erroneously linked the virus to prostate cancer and later to chronic fatigue syndrome (CFS), leading to considerable interest in the scientific and patient communities, investigation of XMRV as a potential cause of multiple medical conditions, and public health concerns about the safety of the donated blood supply.