Histopathological analysis revealed exacerbated arthritis, as observed by enhanced synovial hyperplasia (pannus formation), cartilage destruction, and number of osteoclasts in the double huTNFtg;TgCol6a1-Mir221/222 transgenic mice in comparison to the huTNFtg controls (Figure 2B). Here, MIR221 is linked to arthritic joint disease.