TTF1 and adenoma: This upregulation was confirmed immunohistochemically: by 3 days post Myc activation, intense cytoplasmic CCL9 immunostaining and cell surface immunostaining for the p19 subunit of IL-23 were evident (Figure S4A) in TTF1+ epithelial cells (Stenhouse et al., 2004) while absent from both non-tamoxifen-treated controls (Figure S4B) and tamoxifen-treated KRasG12D-only-driven adenomas (not shown).