Primary endpoint is rate of recurrence of FSGS as seen in renal transplant biopsies and in rate of proteinuria. Secondary endpoint is renal function after transplantation The target subject number is 20 patients and the target population is primary FSGS patients. By the current data, FSGS should recur in 23% of patients. Therefore, it would be expected that at least 4 patients will develop recurrent FSGS after renal transplantation.