Some experimental and clinical studies suggest that mammalian target of rapamycin inhibitors (mTORi) have a specific antiviral effect on BKV tubular epithelial-cell replication, and that conversion from calcineurin inhibitors to mTORi, plus lowering immunosuppression, may prevent the risk of PvAN [13,14]. The gene discussed is MTOR; the disease is BK-virus nephropathy.