CD40 and focal segmental glomerulosclerosis: Inhibition of the CD40-CD40L signaling pathway has proven beneficial in multiple rodent models of kidney disease.15,16,17,18,19,20 Additionally, recent work has demonstrated that patients at risk of recurrent FSGS have high plasma titers of CD40 autoantibodies which produce renal injury in mice.21 These studies suggest that CD40 inhibition would have therapeutic value in the treatment of glomerulonephritis and related renal diseases.