In addition, transcripts associated with increased differentiation and maturation, observed at later stages of colon development E16.5-E18.5 (for example, Klf4 [21], Crohn's disease-related Slc22a5/Octn2 [22], Slc30a4/Znt4 [23], Sst [24]), were expressed at higher levels by tumors from Smad3-/- and Tgfb1-/-; Rag2-/- mice. This evidence concerns the gene TGFB1 and Crohn disease.