"Patients should be more demanding that they are getting the lowest dose possible, " says Gene Saragnese, who runs imaging systems for Philips Healthcare.

WSJ: Reducing Patient Exposure to Radiation From CT Scans

Most prominently, teenager Jesse Gelsinger died from multiple organ failure a few days after receiving a massive dose of virus-based gene therapy in a trial at the University of Pennsylvania.

FORBES: Glaxo Brings Gene Therapy Back From The Dead

In the circadian-gene mutants, however, the enzyme's activity stays steady after a dose of the drug, so tyramine levels remain low.

ECONOMIST: Flying high