The effective antitumor effect of combined treatment (TcES+5-FU) was associated with increased infiltration of cytotoxic cells, such as natural killer cells (NK), which promote tumor cell apoptosis by releasing granzyme B. In addition, this combined treatment also reduced the expression of murine double minute 2 (MDM2), a P53 repressor, leading to the upregulation of P53 and P21, suggesting that combined treatment leads to cell cycle arrest of tumor cells [76]. Here, MDM2 is linked to neoplasm.