SLC15A4 and systemic lupus erythematosus: A series of studies using ethylnitrosourea-induced mutant mice (mice with feeble mutations) and Slc15a4 KO mice revealed that this transporter plays critical roles in TLR7- and TLR9-induced IFN-I production and pathogenic antibody production, which contributes to the antiviral response and pathogenesis of lupus (20, 24, 35, 46, 47) (Figure 2).