TP53 and lip and oral cavity carcinoma: It has been seen that some natural compounds promote the phosphorylation of p53 in ser46; such is the case of the induction of cell death by an extract of Zelkova serrata, which arrests the cell cycle in S-phase, activation of caspase-8 and an increase in the amount of p-p53(ser46) in oral cancer cells in contrast to non-cancerous fibroblasts [41].