TNF and rheumatoid arthritis: TNF, a key inflammatory mediator in rheumatoid arthritis, inhibits osteogenesis by suppressing the expression of osteogenic genes in MP (Col1, Bglap, Runx2), upregulating Wnt signaling inhibitors in synovial fibroblasts (DKK1, SOST, SFRP) [146, 147], and leading to the generation of BMP3, an endogenous BMP inhibitor, by osteoblasts [148].