In addition, we investigated whether the inhibition of CD40-CD40L interaction prevents the effects induced in cultured podocytes and in isolated glomeruli by plasma fractions purified from plasmapheresis eluates obtained from patients with post-tranplant recurrence of FSGS, and we measured the circulating levels of sCD40L in patients affected by FSGS compared to healthy subjects and to patients with membranous nephropathy. This evidence concerns the gene CD40 and focal segmental glomerulosclerosis.