Although the expression of A3G is higher in tumorspheres from colon cancer, A3G expression in clinical specimens of colon cancer is much lower than that of pancreatic cancer in our study, as determined by immunohistochemical staining (P < 0.01, χ2 test) (Fig. 1E; Supplementary Fig. S1), which is similar with the data in the Human Protein Atlas (www.proteinatlas.org). This evidence concerns the gene APOBEC3G and malignant colon neoplasm.