Leukaemia is a cancer of the white blood cells. The type of leukaemia a child develops depends on whether the original cell that gave rise to the leukaemia was destined to be a white blood cell, called a lymphocyte, or a white blood cell called a myelocyte.

• If the cell was supposed to become a lymphocyte, the child will develop Acute Lymphoblastic Leukaemia (ALL).

• If the cell was supposed to become a myelocyte, the child will develop Acute Myeloblastic Leukaemia (AML).