In fact, an important finding was that the immune complexes present in SLE patients serum contain nucleic acids that are internalized via the FcγRIIa, reach the endosome, and stimulate TLR7 and/or TLR9, leading to subsequent activation of transcription factors and IFN-α production [49, 50]. Here, TLR9 is linked to systemic lupus erythematosus.