Important features of XMRV biology include (1) tropism for a variety of cell lines, including prostate cancer DU145 and LNCaP cells [27], [43], [48], and human neural cell types [57], (2) adaptations that
promote growth in prostate epithelium and human - derived prostate cancer cell lines including an androgen response element in the promoter region [58] and downregulation of APOBEC3G [59], and (3) cellular effects with potential oncogenic properties including increased tumor
aggressiveness mediated by downregulation of p27 [60] and differential regulation of several microRNAs [61].