The important roles of TLR4 and TLR9 in IgAN have been studied by several groups, pointing out that their expression was associated with disease severity and even the pathogenesis of IgAN [16–20], but the underlying mechanism of how TLRs led to the pathogenesis of IgA nephropathy is not fully elucidated. The gene discussed is TLR9; the disease is IgA glomerulonephritis.