CD40 and focal segmental glomerulosclerosis: Incubation of podocytes in vitro, both with recurrent FSGS sera and purified anti-CD40-antibodies from recurrent FSGS patients resulted in podocyte depolarization and reduction of overall cell size with decrease of cytoskeletal F-actin expression and injection of anti-CD40-antibody from recurrent FSGS patients in mice led to a mild but significant increase in urinary protein excretion (Delville et al. 2014).