The issue is that a single protein might not be specific enough ie. you will kill lots of wrong things if you are too aggressive. Some people have been working

The issue is that a single protein might not be specific enough ie. you will kill lots of wrong things if you are too aggressive. Some people have been working on combining two (or more) factors in order to only activate when in the right spot: https://www.science.org/content/blog-post/two-steps-activation https://www.science.org/content/blog-post/two-steps-activati... My guess is that this is how the body actually works. At the chemical level, the human body has many highly individually specific things (like enzymes and receptors). However, at the system level, it's probably easier to take two slightly specific things and combine them to make something that is specific enough but not too brittle.