Order from noise: How randomness and collective dynamics define a stem cell
Stem cells are central to organ development and renewal. In most organs, stem cells are located in specific regions and, in some cases, can be identified through several intrinsic properties, like molecular markers. They can differentiate into various types of cells and divide indefinitely to produce more stem cells. However, does this mean the stem cell at the top is immortal? Or can any cell overthrow this? The scientific community is in an open debate whether stem cells actually arise from intrinsic cell properties or from the collective dynamics of the tissue itself. In this second scenario, potential stem cells are in constant competition to sit in certain "niche" regions. Each cell wants to overtake its neighbor by replication and, therefore, continuously pushes them. The functional stem cell will be the one that wins this competition, while losers will be pushed away from the niche, differentiate, and ultimately die.