Furthermore, the alterations are mutually exclusive with USP6 rearrangements, which are detected in ~75 % of primary ABC (vide supra), and were not detected in chondromyxoid fibromas, which are characterized by a complex alteration in chromosome 6 involving the glutamate receptor gene GRM1 in 80 % of cases. This evidence concerns the gene USP6 and aneurysmal bone cyst.