Conversely, in the human-TNF-transgenic (TNF-tg) mouse model, mice express high levels of human TNF-α and develop spontaneous and chronic arthritis.216 The collagen-antibody-induced arthritis (CAIA) and K/BxN STA mouse models also develop arthritis independently of T-cell activation and are therefore used to investigate how GCs mediate innate immune responses in joint destruction. This evidence concerns the gene TNF and arthritic joint disease.