TNF and rheumatoid arthritis: To test the use of AAV-Gα13CA, we utilized three disease models of bone loss: the human tumour-necrosis factorα (hTNFα)-transgene expressing mouse model of autoimmune arthritis24 (named TNFα-RA) (Fig. 6), ovariectomized (OVX) animal model of osteoporosis, (Fig. 7a–d) and calvaria-adjacent lipopolysaccharide (LPS)-injection mouse model of osteolysis (Fig. 7e,f)25.