The scientific magazine PLoS Medicine" reported in its latest edition that an Israeli boy who suffers from a rare genetic disease has developed tumors in his brain and spine after being injected with fetal stem cells, thus raising more doubts among scientists about the usefulness of such therapies.

Scientists from the Sheba Medical Center in Israel explained to the Associated Press that the boy, who suffers from ataxia telangiectasia, had traveled to Russia at age 9, when he was injected with fetal neural stem cells in his brain and spinal cord.

However, in 2005, he began to suffer from headaches. Tests revealed the growth of abnormal cells in the brain and spinal cord fluid. The following year, doctors removed the cancerous cells from the spinal cord fluid, and after analysis it was determined that the origin of the tumors was the fetal stem cells.