The gene they chose is involved in the synthesis of a hormone called gibberellin and, once again, a side-effect of the alteration was to cause the trees to grow faster.

ECONOMIST: GM trees are on their way

When I was a medical reviewer at the FDA in the 1980s, a completely unexpected side effect occurred in the clinical testing of a new formulation of human growth hormone synthesized in bacteria.

FORBES: Commentary

The researchers say it might be possible to use the hormone to develop new drugs to combat impaired learning and memory, but warn that weight gain could be a side effect.

BBC: NEWS | Health | Hunger pangs 'may trigger memory'