IGF1 and rheumatoid arthritis: In addition, the results of this study indicated that the expressions of osteogenesis‐related genes (ALP, OCN, TGF‐β1, and IGF‐1), ALP activity, and positive rate of type I collagen protein were all increased in cells transfected with sh‐lncRNA XIST or let‐7c‐5p mimic, suggesting that the silencing of lncRNA XIST and the upregulation of let‐7c‐5p both promoted osteoblast proliferation and differentiation in RA.