TP53 and neoplasm: To understand the molecular basis of Pu-erh tea action on tumor cell cycle arrest and to test whether mutant p53 is the molecular target for Pu-erh tea action, the p53−/−+S+Ras and p53−/−+Ras tumor cells were treated with 0.2 mg/mL Pu-erh tea water extracts and harvested at different time points to check the molecular response to Pu-erh tea.