For example, CerS1 preferentially produces C18:0 ceramide, which has been implicated in apoptosis and tumor suppression, while CerS5 and CerS6 generate C16:0 ceramide, associated with cell survival and pro-tumorigenic signaling in certain cancers such as head and neck squamous cell carcinoma (HNSCC) [69]. This evidence concerns the gene CERS6 and head and neck squamous cell carcinoma.