FCGR2B and systemic lupus erythematosus: It has been shown that mice without targeted alleles but congenic for the 129 derived distal-region of Chr1 (Sle16), a lupus-associated region including the autoimmune-prone haplotype 2 of the Slamf genes and the haplotype I of the FcγRIIb gene, develop a similar autoimmune phenotype as C57BL/6 Sle1 congenic mice (111).