Cells which have potential to turn into different kinds of cells and power to renew itself are called “stem cell”.
Cells, which are called as “stem cells” nowadays, have some important and distinctive particularities than our normal somatic cells that are found in our organism in essence.
Most substantial ones of these particularities are their ability of high reproduction capacity and regeneration into other types of cells in our body. Due to their abilities of reproduction in living creatures and under laboratory conditions without losing their ability to be differentiated for a long time (self renewal) and to be differentiated into similar or varied tissues/organs’ cells in response to proper signals (generally damage signals in living creatures and varied chemical stimulants in laboratories); they have become substantial biological materials to be used in cell based treatments primarily, in experimental developmental biology, in drug toxicity studies and in understanding pathogenesis of diseases.
Stem cells sustain their high regeneration potentials due to high telomerase enzyme activities in one hand; they also maintain this function without being differentiated thanks to continuing expressions of transcription factors which are responsible for self renewal due to activation of some signal pathways, generated by microenvironments (niches), in which they dwell.