Good overview of the immune system. Liked the drawings and repetition. Find that not enough non-fiction books repeat things. But maybe things were over simplified, especially with the analogies. A lot of the analogies just made things harder to follow, since you have to parse the analogy in addition to what is actually happening. And kind of panders to the reader, saying that things are complicated. Instead of dedicating space to pandering, should have just repeated things in new ways or introduced more richness.