TLR7 and systemic lupus erythematosus: Using an IPA search for the top-ranked canonical pathways that are commonly responsible for autoimmunity and viral infection, “pattern recognition”-related genes, such as toll-like receptor (TLR), both expressed on the cell surface (TLR4) and intracellularly (TLR7), and DDX58 (DEAD [Asp-Glu-Ala-Asp] box polypeptide 58, alternatively called RIG-1) [26] were enriched in all cell types from patients with SLE and immunised ND, suggesting the existence of former viral responses in the disease history of the SLE patients.