A specific receptor for CXCL12, CXCR4 was expressed on a higher proportion of B lymphocytes in OB patients, whereas CXCL12 plasma concentrations were lower in OB and T1D groups compared to controls, suggesting the involvement of CXCL12/CXCR4 axis in these diseases. This evidence concerns the gene CXCL12 and type 1 diabetes mellitus.