In vivo studies demonstrated that 5-FU and β-elemene combination treatment can significantly inhibit the tumor volume, and the effect is higher than that of the single agent in the HCT116p53−/− all line xenograft model constructed from 5-fluorouracil-resistant p53 deficient colorectal cancer HCT116p53−/− cells [65] (Figure 5). This evidence concerns the gene TP53 and neoplasm.