TKTL1 and oral cavity squamous cell carcinoma: TKTL1 is overexpressed in a range of human malignancies including breast, colon, ovary, lung, nasopharynx, gastric, renal, cervical, lung and liver cancers, and increased TKTL1 levels were shown to be associated with reduced survival for patients with cancers of the colon, oropharynx, bladder and with oral squamous cell carcinomas [18–24].