I can sense readers’ puzzled looks, an eyebrow raised over your book or gadget. Haven’t you already read in this book that some other cell or substance is the first line of defense? Yes, you are correct to raise an eyebrow. You are not missing something. The thing is, the immune system has multiple overlapping, sometimes redundant first lines of defense, and second lines too. This festival—our take-all-comers cocktail party—is nothing if not chaotic and multifaceted. There also is method to the madness. Multiple actors roam the party, using different tactics, often overlapping.
