CERK and head and neck squamous cell carcinoma: Thus, although clinical trials on sphingolipids in HNSCC have been limited, GluCS inhibitors, SphKs inhibitors (PF543, FTY720, and ABC294640), CerK inhibitors, anti-S1P antibodies, and synthetic ceramides (Section 6, Section 7 and Section 8) against HNSCC should be validated in clinical studies.