Another factor in the relationship between genetic composition and observable traits is the way that proteins can sometimes be modified. For example, protein enzymes can be turned on and off, thereby altering their function and activity.
遗传组成和可观测性状间关系的另一要素是蛋白质有时是可以修改的。比方说，蛋白酶可以开启或关闭，并借此改变蛋白质的行为和功能。像其他形式的基因表达一样，貌似由一系列先天及环境因素的组合来驱动这一过程。