RAC1 and head and neck squamous cell carcinoma: Yet, we would like to point out that with the current lack of publicly available/testable HNSCC models bearing endogenous RAC1-A159V mutation, our in vivo drug sensitivity finding using RAC1-A159V-engineered HNSCC models should only serve as a proof-of-concept finding to support future validation in HNSCC models with endogenous RAC1-A159V mutation, when they become available.