“…This suggestion was strengthened by in vitro and animal experiments with BKPyV that proved its transforming ability as reviewed previously [1,3,6]. After the primary infection, BKPyV establishes a lifelong persistent infection in the urinary tract and renal cells [2], hence there exist large number of studies of urinary tract neoplasia and cancers [7,8,9,10,11,12,13,14,15]. DNA, RNA or even proteins of the BK virus have been detected in different human tumours (brain, neuroblastoma, osteosarcoma, bladder, kidney, adrenal, prostate, genital, colon), but the role of BKPyV in human cancers is still controversial [1,4,6,16,17,18,19].…”