DPP4 and colorectal carcinoma: It has been shown that apigenin alone is able to cause an increase of 56.3% in the cell surface abundance and activity of CD26 in different CRC cell lines (HT-29 and HRT-18), so some authors have studied whether this flavone is able to enhance the up-regulation in CD26 cell surface expression of irinotecan, 5-FU and oxaliplatin, that are three chemotherapeutic agents used for the treatment of colorectal cancer.