There are many different types of cancer, but they all have one thing in common: errors in the signals that control normal cell behavior can cause uncontrolled cell growth and cell division, leading to a tumor. An enzyme called SHP2 plays a key role in this regard. SHP2 is a signaling molecule that in its activated state stimulates cell proliferation. In a normal healthy body, the rates of cell proliferation and cell death are balanced and tumors do not develop. However, if SHP2 becomes too active, the number of cells being created outweighs the number that die, which can lead to the formation of dangerous tumors. Enhanced SHP2 activity resulting from genetic mutations has been shown to play a central role in a number of types of leukemia.