Idiopathic Focal Segmental Glomerulosclerosis is a disease without a healing treatment and which causes kidney failure. Kidney transplantation is the best solution but not the last, because in the 40% of patients the disease returns. The Kidney Physiopathology group at CIBBIM- Nanomedicine/VHIR and the Nephrology Service at Vall d’Hebron University Hospital have discovered a modified protein, the Apolipoprotein A-I (ApoA-Ib), that is related with recurrence of FSGS and could be used as a predictor biomarker to determine in which patients the disorder can reappear. VHIR researchers, together with 14 groups of the Spanish Renal Transplantation Group (GREAT) have identified this protein in a study using proteomic techniques. The results of this study, published at the "http://onlinelibrary.wiley.com/doi/10.1111/j.1600-6143.2012.04338.x/abstract" American Journal of Transplantation, suggest that the presence of this protein in the urine of the patients indicates that they are starting a relapse. Its detection, in the early postoperative after a kidney transplantation, is crucial because let the doctors to adopt different therapeutic measures. For its immediate application, researchers have already transferred the patent of this protein.