TP53 and neoplasm: The physiological functioning of p53 and epidermal growth factor receptor (EGFR) intracellular signalling pathways are critical for cellular DNA-damage response (DDR)-mediated repair of damaged DNA; but in oral SCC the expression of p53 mutations and of EGFR gene are upregulated so that the capacity of repair of damaged DNA is enhanced leading to increased longevity of tumour cells, and tumour resistance [40].