IFNG and Osteopenia: (i) proliferation of splenocytes and FLS ↓ (ii) FLS invasion ↓(iii) apoptosis of FLS and splenic T cells ↑(iv) proliferation ↓↓, apoptosis ↑↑ of activated cells (v) cytokine (IFNγ, TNFα, and IL-6 induced by NF-κB) production ↓ (vi) inflammatory cell infiltration (T cells, B cells, macrophages) ↓(vii) bone erosion ↓(viii) pannus formation ↓(ix) expression of CD3, CD79a, CD11b, COX1, and factor VIII in the joints ↓(x) expression of TLR-2, -3, -4 in the peripheral blood and cultured FLS ↓(xi) disappearance of soft tissue swelling, focal osteopenia, and bone erosion on CT images