ESR1 and systemic lupus erythematosus: in the NZM2410 and MRL-lpr strains, suggest that in genetic backgrounds that show a strong female sex bias, such as in (NZB × NZW)F1, B6.Sle1, and B6.Sle1b mice, disruption of ERα may reduce autoimmunity and/or lupus pathogenesis via mechanisms that are distinct from those in genetic backgrounds that do not show a female sex bias, such as the NZM2410 and MRL-lpr strains.