Cell therapy implies treatment using autologous (patient's own) or allogeneic (donated) cells. The cells transplanted can substitute the missing or sick cells or their components or can be used to achieve other therapeutic effects, such as changes of the immune system and  attack on cancer cells. .Apart from that, the transplantation of haematopoietic stem cells has been used for years to treat certain blood disorders and different types of cancer, as well as conditions of severe immunodeficiency and congenital metabolic disorders.