CSF3R and systemic lupus erythematosus: One region is Sle2c that encodes several genes including the G‐CSF receptor (Csf3r), which carries a nonsynonymous mutation in the extracellular domain that confers resistance to lupus.41, 42 This is a loss‐of‐function mutation, as G‐CSF binding was impaired and G‐CSF treatment failed to mobilize BM neutrophils, indicating that B6.Sle2c2 mice are resistant to developing lupus due to their inability to mobilize G‐CSF‐responsive BM cells.43