XIAP and head and neck squamous cell carcinoma: Regarding apoptosis inhibition by IAPs, as recently reported, high expressions of cellular inhibitor of apoptosis protein 1 (c-IAP1), X-linked inhibitor of apoptosis protein (XIAP), and Apollon observed in HNSCC patients were associated with the low survival rates and cisplatin resistance (43–45, 69) (Figure 2C; Table 1).