For example, monoclonal antibodies against NOTCH have been shown to reduce the cancer stem cell (CSC) population in CRC tumors [37], with clinical trials of therapeutic antibodies against DLL4 in combination with FOLFIRI (irinotecan, folic acid, leucovorin, and fluorouracil), ongoing in the metastatic CRC setting (NCT01189942). Here, DLL4 is linked to colorectal carcinoma.