Stem cells, computer artwork. Stem cells in the form of a question mark, representing the lack of understanding of stem cells and their potential as a treatment for many disease. Known as precusor cells, stem cells undergo differentiation to form the different cell lineages required to produce the body's specialised tissues. For example, stem cells in bone marrow go through a process called haemopoiesis and develop into either red blood cells or one of several types of white blood cells that make up the immune system. Stem cell research involves trying to use stem cells to repair or replace diseased tissues or organs.