TLR9 and systemic lupus erythematosus: In summary, autoimmune responses to NETs studied so far provide evidence for NET-DNA (gDNA/ mtDNA) as a TLR9 ligand and as an adjuvant promoting IFN production and polyclonal proliferation of B cells, including DNA reactive B cells in SLE, RA (81), psoriasis etc. However, there is little evidence to suggest that NET-DNA serves as a direct autoantigen for DNA-reactive B cells.