<qa>  What is the first dose level of cyclophosphamide?Patients will receive a non-myeloablative lymphocyte-depleting preparative regimen consisting of cyclophosphamide 60 or 30 mgkgday x 2 days i.v. and fludarabine 25 mgm2day i.v. x 5 days. Following this regimen, patients will receive one single intravenous adoptive transfer of transduced T cells starting with the first dose level. 