However, mutations in EXT1 are known to be the cause of hereditary multiple exostoses (HME), an autosomal dominant disorder characterized by benign bone tumors on the active bone growth areas [36], emphasizing its role as a tumor suppressor, increased EXT1 DNA copy number alteration (DCNA) has also been reported in aggressive bone tumor [37]. The gene discussed is EXT1; the disease is hereditary multiple exostoses.