If you want a thicker yogurt, you can also add one-third of a cup of dry milk.

VOA: special.2009.01.19

You're taking advantage of a promoter system, or a gene activation system, that this species knows about because adult animals can make milk.

我们之所以能利用这个启动子系统,或者称之为可以被这一物种识别的,基因活化系统,是因为成年动物可以泌乳

耶鲁公开课 - 生物医学工程探索课程节选