It turns out there's actually no natural function known in the body for lithium.

事实上我们已知的身体机能,在正常情况下根本不需要锂。

麻省理工公开课 - 化学原理课程节选

You can become dehydrated and die just as a result of the loss of water there, because of your body's natural response to the infection.

就会脱水,而失水的后果就是死亡,这是你身体对于这种感染的自然反应

耶鲁公开课 - 生物医学工程探索课程节选

This is introducing a gene, it's a natural gene but it's not - it's a natural gene that's found in humans and is actually expressed all over your body in different levels, but you're concentrating it or over expressing it in one particular region of tissue in order to have a particular effect.

通过导入一个基因,这是一个天然基因但--,是一种于人体内发现的天然基因,在全身细胞中都有不同程度表达,但需要集中在组织的某一特定区域,表达或过表达,才能达到特定疗效

耶鲁公开课 - 生物医学工程探索课程节选