PIK3CA and head and neck squamous cell carcinoma: In contrast, after detailed statistical analyses, another study [106] enrolling the clinical data of HNSCC patients collected by the authors and TCGA database showed that PIK3CA mutations (HR = 0.45, p = 0.021) were a potential predictor of ICI efficacy and that PIK3CA mutations correlated with good overall survival in HNSCC patients, suggesting that PIK3CA mutations could identify patients who would benefit from ICI therapies in HNSCC patients.