In conclusion, our WES analysis confirms that the osteosarcoma karyotype is complex, however, we found genes probably involved in osteosarcoma carcinogenesis, as KMT2C, and we identified a group of 15 genes probably involved in metastasis development and drug resistance that could offer the opportunity to identify potential drug targets in order to create a personalized therapy and increase the survival rate among young patients with osteosarcoma. The gene discussed is KMT2C; the disease is osteosarcoma.