The stem cells are primitive cells, produced during the development of the organism and that have capacity to generate different cellular types, to reconstitute several woven and of solemnity-replying. Two stem cells types exist, the embryonic ones, derived of the apprenticeship of blastocisto of the embryo and the adult ones (hematopoieticas) originated, mainly, of the bone marrow and of the blood of the umbilical cord. These cells bring the possibility to regenerate weakened parts of the body and of curing diseases that still challenge the treatments with drugs.