LSP1 is a negative regulator of leukocyte trafficking and activation,28 which has been replicated across multiple GWAS for BrCa incidence6,24,25,26,27 and outcome,29,30 as well as inflammatory and autoimmune diseases,31,32,33,34,35 yet the therapeutic potential of LSP1 is unknown. This evidence concerns the gene LSP1 and autoimmune disease.