Progenitor cells are stem cells that are already partially differentiated.
Replication of progenitor cells
Both may differentiate into different cell lines but, although true stem cells can theoretically regenerate indefinitely, progenitor cells are only able to replicate a limited number of times. Most progenitor cells like dormant in the tissues most of the time, but can react to injury and begin to replicate and differentiate to aid in healing.
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Mesenchymal Stem and Progenitor Cells in Regeneration: Tissue Specificity and Regenerative Potential. Rohban R and Pieber TR. Stem Cells Int. 2017; 2017: 5173732.