IL4R and rectal cancer: Compared with other existing targeting regents for rectal cancer, such as the anti-Epithelial cell adhesion molecule,45 Interleukin-4 receptor α,46 transferrin receptor,47 epidermal growth factor,48 αvβ5 integrin,49 hyaluronic acid,50 and chitosan,51 folic acid is more cost-effective and folic acid conjugated lipids (such as DSPE-PEG-Folic acid) are already commercially available, avoiding the need for additional conjugation steps and minimising the synthesis complexity.52