Fig 1. A schematic illustration of the crypt’s structure and cell lineage classification.

Panel A) A cartoon of the intestinal crypt and the relative location of cells of different lineages. Panel B) A diagram of cell lineages. Stem cells give rise to terminally differentiated enterocytes, Goblet and Paneth cells, depending jointly on Wnt concentration as well as Notch expression of that cell’s neighbors. Only Paneth cells undergo apoptosis, since Goblet cells and enterocytes naturally undergo anoikis upon reaching the top of the crypt.