Our analyses reveal that Stat3 activity is tightly linked with proliferation, that Stat3-responsive cells of zebrafish intestinal folds co-localize with the stemness marker Sox9b (Aghaallaei et al., 2016), and that gut cellular activities are dependent on a Wnt/β-catenin/Stat3 signalling cascade, both during tissue formation and tumour growth. This evidence concerns the gene STAT3 and neoplasm.