DPP4 and neoplasm: The results showed that the expression of IPCEF1, TFF3, GLT8D2, TPO and DIO1 were downregulated in the tumor group and DPP4, LRP4, CDH3, KCNJ2, CLDN1, GABRB2, FN1 were upregulated in the tumor group (Figure 2B-E).