It is important to note that rearrangements in the USP6 gene are not unique to ABC and that they have been described in other benign entities, such as nodular fasciitis, myositis ossificans, fibro-osseous pseudotumor of digits and in a subset of fibroma of tendon sheath, all sharing similar clinical and histopathological findings with ABC. The gene discussed is USP6; the disease is aneurysmal bone cyst.