CXCR5 and autoimmune disease: DNs have been further divided into two subgroups, based on the expression of follicular homing marker CXCR5.24 The CXCR5+ subgroup (DN1) is expanded in healthy elderly individuals and lacks T-bet expression, while the CXCR5- subgroup (DN2) expresses T-bet and is more marked in autoimmune diseases.22,24,25 The immunophenotyping profile markers for the characterisation of DN subgroups are listed in Table 2.