The median OPG expression level was 3731 (range, 1128–28,413) for FD, 2683 (range, 2069–6643) for chordoma, 2210 (range, 107–14,942) for chondrosarcoma, and 1657 (range, 149–16,049) for osteochondroma (Fig 3). This evidence concerns the gene TNFRSF11B and Osteochondroma.