Finally, thank you to the editor and referees for the constructive feedback.

Whereas gut epithelial remodeling in pregnancy/lactation is reversible, constitutive activation of RANK drives intestinal expansion and prevents the formation of Apcmin-driven small intestinal stem cell tumors.

Babies born to females that lack Rank in the intestinal epithelium show reduced weight and develop glucose intolerance upon metabolic stress.

Receptor activator of nuclear factor kappa-Β (RANK) and its ligand RANKL were identified as a molecular pathway involved in this villous expansion of the small intestine in vivo in mice and intestinal murine and human organoids.

We report that the intestinal epithelium expands during pregnancy and lactation in mice. This enlargement of the intestinal surface area is reorganized into sheet-like geometries.