Figure 2.  In the cells culture, progenitors AC are yellow, progenitors NAC are light blue and differentiated AC are dark blue and differentiated NAC are purple.

 Fas-ligand is red and GF is green.

Figure 3. Growth of cells cultures.

After several divisions, progenitors (yellow) become reticulocytes (blue) which produce a growth factor : Fas-ligand (red halo).

 After one cycle, reticulocytes become erythrocytes ( purple ): cells do not divide in this model.