Stem cell research. Researcher's hand holding a tube being used to culture stem cells. The pink liquid is a nutrient broth that supports the growth and development of the stem cells. Stem cells are cells that differentiate to form the range of different tissues found in the human body. The type of cell they mature into depends upon the biochemical signals they receive. Stem cells are found in bone marrow, umbilical cord blood and embryos. Stem cells are being studied to find treatments for disorders of the blood and organs such as the heart, brain and kidneys. This work is being carried out at the Stem Cells Research Institute (SCRI) in Milan, Italy.