PIK3CA and head and neck squamous cell carcinoma: HNSCC patients could benefit from BYL719 inhibitors, and depletion of MYC, p53 mutation, or YAP especially potentiates patients.293 Combining BYL719 with KTN3379, a monoclonal antibody targeting HER3, enhanced the suppression of HNSCC in vivo.294 However, some HNSCC cells with PI3K-independent activation were resistant to PI3K-independent activation.