MET and head and neck squamous cell carcinoma: However, certain limitations are inevitable in our study: 1) we only reported the 18F-c-Met peptide imaging results in male mice not in females, gender-specific differences in effective dose and biodistribution might occur; 2) we haven’t tested whether it can differentiate between high and low c-Met-expressing HNSCC; 3) we haven’t tested the usage in other types of tumor models.