Figure 1: Laboratory trend of serum creatinine levels (line) and CMV DNA on plasma (bars) over time and therapy administered. Ten days after the start of GCV therapy genetic screening disclosed a mutation of the CMV UL97 gene at codon C603W. GCV was suspended and antiviral therapy switched to foscarnet with dosage adjusted for the patient’s weight and kidney function (6 g/die). At the same time the immunosuppressive regimen was modified with the introduction of everolimus, minimizing tacrolimus dosage. Two weeks after initiating this new therapeutic approach, the patient presented a clearance of viral load with no repercussions for kidney function. This trend persisted at three years after transplantation with serum creatinine level of 1.3 mg/dL.