"From his reading in the library, Allison knew that researchers had found these blobby amoeba-like cells to be more than just garbagemen; they were also frontline reporters bringing back updates from the constant battle against disease. When they found something interesting and foreign, they carried pieces of those strange, non-self proteins (or “antigens”) back to the lymph nodes, to show them around like wanted posters. (Lymph nodes are like Rick’s in Casablanca. Good guys, bad guys, reporters and soldiers, macrophages, dendritic cells, T and B cells, and even diseased cells, everyone goes to Rick’s.) The information triggered other cells in the adaptive immune system to ramp up into a massive clone army in specific response."