FN1 and rheumatoid arthritis: Interestingly, an activation of the Wnt/β-catenin signaling in chondrocytes induces cartilage matrix degradation similar to that which occurs in osteoarthritis and RA, whereas the blockade of Wnt signaling facilitates bone erosion and might contribute to the catabolic model in the bone remodeling observed in RA patients, in which the canonical Wnt pathway was able to regulate the expression of fibronectin and metalloproteinase [7, 18].