Multipotent stem cells can give rise to several other cell types, but those types are limited in number. An example of multipotent cells is hematopoietic cells—blood stem cells that can develop into several types of blood cells but cannot develop into brain cells. At the end of the long chain of cell divisions that make up the embryo are terminally differentiated cells—cells that are considered to be permanently committed to a specific function.

Scientists have long held the opinion that differentiated cells cannot be altered or caused to behave in any way other than the way in which they have been naturally committed. New research, however, has even called that assumption into question. In recent stem cell experiments, scientists have been able to persuade blood stem cells to behave like neurons, or brain cells. Scientists now believe that stem cell research could reveal far more vital information about our bodies than was previously known. There is also continuing research to see if it is possible to make multipotent cells into pluripotent drugs.