MTOR and Crouzon syndrome-acanthosis nigricans syndrome: On the other hand, 5 patients had graft failure (2 due to chronic allograft nephropathy and 3 due to unknown causes) in the mTOR inhibitor group and 11 patients lost their grafts (1 due to acute antibody-mediated rejection and 10 had chronic allograft nephropathy) in the non-conversion group.