Understanding Stem Cells

The human body has different organs. Stem cells are basic cells that give rise to all cells in these organs. There are multiple types of stem cells including totipotent stem cells (zygotes), embryonic stem cells, and adult stem cells.

Embryonic stem cells come from blastocysts. In the lab, embryonic stem cells are donated from leftover embryos created during in-vitro fertilization. They are pluripotent, meaning they can form any cell in the body but not the cells in the umbilical cord or placenta.

Adult stem cells are found in some organs, such as the skin, and are multipotent. This means they can only become a few different cell types related to the organ where they're found.

Scientists can induce a regular body cell to change into a pluripotent stem cell. These induced pluripotent stem cells can become any type of cell in the body.

Scientists study stem cells to learn how they become different types of cells. Stem cell therapy uses stem cells to treat diseases. Current stem cell therapy treats diseases and cancers of the blood, like leukemia.

In stem cell therapy for leukemia, hematopoietic stem cell transplantation, doctors take a sample of blood or bone marrow from the patient or a donor. The patient receives chemotherapy to kill abnormal blood cells and then receives a transplant of healthy hematopoietic stem cells.