TNFAIP3 and arthritic joint disease: The postulation that deficiency of A20 leads to a plethora of inflammatory IL-6 that drives Th17 differentiation has been confirmed in an arthritis-related study where A20 inhibits Th17 cell differentiation through IL-6 in mice lacking A20 in their bone marrow mesenchymal stem cells (BM-MSCs) (138, 204).