Fig. 6. Summary of experimental results. Keratinocytes are shown as wild type (WT) or expressing DeltaFl (Fl), DeltaDS (DS) or DeltaVA (VA). Black arrows represents signal from Delta-expressing cell to WT cell; Double-headed arrow represents reciprocal signalling between two Delta-expressing cells. The differentiation signal is represented by three sizes of blue arrow, the thinnest representing no enhanced differentiation, the thickest representing a strongly increased signal, and the medium arrow differentiation that is slightly enhanced. Intercellular adhesion (cohesion) is shown as being promoted (pink arrow) or not (crossed through arrow).