In their study, CD40 autoantibody alone had the best correlation (78% accuracy) with recurrent FSGS risk after transplantation; interestingly injection of CD40 autoantibody obtained from recurrent FSGS patients enhanced human suPAR-mediated proteinuria in wild type mice, suggesting the possible synergy between CD40 autoantibody and suPAR (49). Here, CD40 is linked to focal segmental glomerulosclerosis.