TLR9 and systemic lupus erythematosus: By engaging with the Fc γ receptor II (FcγRII), anti-dsDNA antibodies facilitate receptor-mediated DNA endocytosis, allowing cfDNA to enter the endosomal compartment of plasmacytoid Dendritic Cells (pDCs) containing Toll-like Receptor-9 (TLR-9), subsequently initiating a robust activation of the interferon pathway, leading to disease progression in SLE (Bai et al., 2017).