Figure 1.

Hierarchy of stem cells with cell determination, differentiation and maturation. It also shows potential areas of A. Trans-germal plasticity – differentiation from one stem to other stem cell type; B. De-differentiation – regression of a fixed lineage cell type to a more primitive cell type; C. Trans-determination – differentiation from one progenitor cells to another; and D. Trans-differentiation – hypothetical differentiation of one cell type to another without dedifferentiation.