Although great improvement has been obtained for CRC drug therapy besides surgery in the past decades, especially the applications of checkpoint blockades (antibodies against PD-1 and PD-L1) in CRC therapeutic regimens in addition to 5-FU-based chemo-drugs, EGFR and VEGF antibodies, and small molecules targeting mutant KRAS and BRAF [43,44], the prognosis for patients with advanced and metastatic CRC remains suboptimal. Here, KRAS is linked to colorectal carcinoma.