“…It resides in the kidneys in a latent or persistent state, but can be reactivated upon immunosuppression of the host and is associated with hemorrhagic cystitis and polyomavirus nephropathy (Arthur et al, 1986;Hiraoka et al, 1991;Pappo et al, 1996;Randhawa et al, 1999;Li et al, 2002). BKV oncogenically transforms rodent cells in culture, causes kidney tumors in transgenic mice, and transforms primary human cells in culture when coexpressed with an activated ras oncogene (Portolani et al, 1975;Pater and Pater, 1986;Small et al, 1986;Dalrymple and Beemon, 1990). BKV has been reported to be detected in a number of human tumors, including those in the urinary tract, brain, pancreatic islet, lung, eye, liver, Kaposi's sarcoma, and bone (reviewed in Imperiale, 2000Imperiale, , 2001Reploeg et al, 2001;Tognon et al, 2003).…”