TP53 and head and neck squamous cell carcinoma: On the contrary, mutations found in HPV-negative HNSCC cases inactivate the function of tumour suppressors such as p53, favouring glycolysis; since when p53 is functionally active, it induces the inhibition of glycolysis mainly through the activation of the protein TP53-induced glycolysis and apoptosis regulator (TIGAR) and the repression of glucose transporter 1 and 4 (GLUT1 and GLUT4) [38].