How can stem cells produce both new stem cells and specialized cells?

Stem cells maintain their populations and produce specialized cells through a process known as asymmetric stem cell division.1

In this process, a single stem cell divides to produce two distinct daughter cells:
* Self-renewal: One daughter cell remains a stem cell, effectively replenishing the stem cell population and ensuring its persistence over time.12
* Differentiation: The second daughter cell becomes a progenitor cell (or transit-amplifying cell), which is targeted for specialization.31

These progenitor cells undergo a limited number of divisions, becoming increasingly specialized with each round until they reach terminal differentiation, where they develop the distinct structures and functions required for specific tissues and organs.1

This balance is tightly regulated by the cell's environment. Stem cells reside in specialized niches where they receive signals—such as growth factors or hormones—that influence gene expression and dictate whether a cell will continue to self-renew or commit to a specific developmental pathway. Additionally, systems like lateral inhibition allow neighboring cells to communicate, ensuring that only a specific number of cells differentiate while others remain as precursors to support ongoing tissue regeneration.314