TLR9 and focal segmental glomerulosclerosis: One feasible approach for the study could be to perform immunohistochemical staining of TLR9 with renal biopsies in a cohort of LN consisting of patients with MCD/mesangial proliferation and FSGS; and then test whether TLR9 de novo expression in podocytes correlates with the patients with FSGS, which manifests with podocyte injury and loss in contrast with MCD.