IL4 and digestive system cancer: In consideration of a colon-rectal cancer diagnosis of his father at the age of 45 years, we carried out a Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Pymol-based Protein Data Bank study and found that interleukin-4 (IL-4) may be the key factor supporting the occurrence of hyperplastic polyps in collagenous gastritis (Fig. 4).