Our immune system's function is to keep us healthy in the face of an environment where there are lots of things that could potentially harm us.

我们免疫系统的功能就是保持自身健康,在面对危机四伏的环境时,使我们免受伤害

耶鲁公开课 - 生物医学工程探索课程节选

Fungi which don't often cause infections in people with healthy immune systems but can under some circumstances, and can be tremendous problems in patients that have weakened immune systems.

真菌在免疫系统健康的情况下通常,不引起感染,但在某些情况下也会感染,那就成了极大的问题,在免疫系统脆弱的病人体内

耶鲁公开课 - 生物医学工程探索课程节选