CDKN2A and neoplasm: Percutaneous needle biopsy of the left proximal tibia was interpreted as an osteoblastic osteosarcoma (Fig. 1D).The immunohistochemical (IHC) analysis showed that the p16 protein was present in more than 50% of tumor cells and a strong positive vimentin expression was detected (Fig. 1E).The patient received neoadjuvant chemotherapy consisting of cisplatin (120 mg/m2), ifosfamide (2 g/m2), and doxorubicin (75 mg/m2) for two cycles.