TLR5 and systemic lupus erythematosus: To determine the leukocyte subset expression pattern of β-catenin and to determine whether an additional lupus-prone strain also lacked leukocyte β-catenin expression, we isolated splenocytes from healthy B6 and lupus-prone B6.Sle1 and B6.Sle1.Yaa mice and stained them intracellularly with anti-β-catenin or isotype control antibody and analyzed by flow cytometry.