DPP4 and colorectal carcinoma: Figure 2B shows the level of CD26 in liver metastasis of scramble and shCD26 cells. The development of liver metastasis was confirmed by H&E and anti-human Ki67 staining (Figure 2B). These results revealed that the metastatic potential of CRC cells was significantly impaired by CD26 repression (Fisher’s exact test, p = 0.003).