CD40 and focal segmental glomerulosclerosis: Based on the level of antibodies, patients with MCD and FSGS can be divided into two subgroups: patients with steroid-sensitive MCD and FSGS are characterized by high level of anti-UCH-L1 antibodies and a low levels of anti-CD40 antibodies; while patients with steroid-resistant FSGS, on the contrary, are characterized by high levels of anti-CD40 antibodies and low levels of anti-UCH-L1 antibodies.