In each of the following examples of contact signaling between adjacent cells in the mammalian gut epithelia, indicate whether the signaling is mainly mediated by Delta (D) or Ephrin (E) signals. Your answer would be a three-letter string composed of letters D and E only, e.g. EDE.
( ) Separation of crypt cell types from villus cell types
( ) Regulation of stem-cell differentiation by Paneth cells
( ) Differentiation of transit amplifying cells into either secretory cells or absorptive cells