ENPP2 and synovitis: However, we found that ∆ATXCtsk mice were remarkably protected against bone degradation induced by two independent powerful inflammatory challenges such as lipopolysaccharide (LPS) treatment and transfer of the serum from mice expressing the transgenic T cell receptor (TCR) and the MHC class II allele Ag7 (K/BxN), while, as expected, specific inhibition of ATX expression in mature osteoclasts does not affect the onset and progression of the inflammatory process or the accumulation of ATX in the synovitis of ∆ATXCtsk mice [15].