Nursing neurons: “The first gene therapy trial for Alzheimer’s
disease begins.”

In treating neuro-degenerative diseases, gene therapy
provides an alternative to implanted neurons derived from
human embryos or fetuses. Gene therapy avoids this ethical
problem, but was severely tarnished by the death of teenager
Jesse Gelsinger during a 1999 gene therapy trial, which aimed
to correct a liver defect.

New Scientist