Stem-cell therapy is the use of stem cells to treat or prevent a disease or condition. Stem cells are biological cells that can differentiate into specialized cells and can divide through mitosis to produce more stem cells.
In humans, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing adult tissues.
Bone marrow transplant and blood derived stem cells are the most widely used stem-cell therapy, but some therapies derived from umbilical cord blood are also in use.