 - Grade 2 acute Graft versus Host Disease aGvHD at time of infusion of natural killer NK cell infusion. Patients with treated aGVHD must be on a stable dose of therapy no increase in immunosuppressive therapy for the 2 weeks before planned natural killer cell infusion NKI. The dosagelevel of immunosuppressive therapy at the time of NKI should be no greater than 1 mgkg of prednisone daily or mycophenolate 1000 mg bid daily or cyclosporine with a target level of 200 or equivalent. 