A number of indicators have been reported in the head and neck tumors to predict the resistance of cetuximab, such as EGFR expression [19], EGFR gene polymorphism [4], EGFR VIII expression [20], EGFR expression in the nucleus [3], methylation of EGFR [21], ErbB pathway and MET activation [22], and Axl overexpression [23] and changes in the downstream pathway of EGFR, such as HRAS mutation, deletion of PTEN gene [24], and abnormalities in the PI3K pathway [25]. This evidence concerns the gene PIK3CA and neoplasm of neck.