Figure 1.

(a) Scheme of a colon crypt including some of the niche factors controlling cell fate. TA cells, transient-amplifying cells. Created with Biorender.com (accessed on 27 April 2021). (b) Morphology of human colon normal (PDO) and tumor (PDTO) organoids. Upper panels: light microscopy images. Middle panels: hematoxylin and eosin (H&E) staining. Lower panels: electron microscopy images showing the common undifferentiated phenotype of cells in both types of organoids (decondensed euchromatin, lack of villi, scarce cytoplasmic organella). ECM, extracellular matrix (Matrigel); L, lumen. Images shown are unpublished and correspond to studies by our group.