What Is a Stem Cell Niche?

Niche has become the most important issue in stem cell biology, but it is still a hypothetical notion that cannot be defined in a better way than the microenvironment surrounding stem cells. Using a melanocyte stem cell system as a model, we have analyzed the cellular and molecular requirements for differentiation of quiescent stem cells. Our results demonstrate the multiple subsets within the stem cell compartment and thus suggests the complexity of niche. [ABSTRACT FROM AUTHOR]