TLR7 and systemic lupus erythematosus: The rationale for selecting SLE is twofold: some SLE risk alleles act to augment the interferon response (e.g. IRF5, IRF7, CXORF21-TASL); other lupus susceptibility genes act in the intracellular viral sensing (e.g. IFIH1, TLR7, RNASEH2C) pathway.