Using viruses as vectors for the genes is a disturbing risk. "Many viruses are formidable foes," Yang explains, "and even after being broken down they may still re-form or mutate, and revive once inside the body." The possibility of this occurring may be miniscule--perhaps 100 million to one in the past, and 10 trillion to one given recent advances--but it cannot be overlooked.
利用病毒作為載體就是一項令人憂慮的冒險，「許多病毒魔高一丈，雖然經過分解，但在人體內也有可能重新組合或突變而活化」，楊文光說，雖然這種可能性微乎其微，過去是億分之一，現在技術可以做到十兆分之一，但仍不可大意。