SP7 and gout: MSU crystals contribute to bone erosion in gout through the formation and activation of osteoclasts and decreased viability, function, and differentiation of osteoblasts, due to a reduction in mineralization and the expression of genes related to osteoblast differentiation, such as Runx2, Osterix (Sp7), Bone Sialoprotein (Ibsp), and Osteocalcin (Bglap).