Strep throat! Hay fever! Influenza! The world is a dangerous place for a red blood cell just trying to get her deliveries finished. Fortunately, she's not alone...she's got a whole human body's worth of cells ready to help out! The mysterious white blood cell, the buff and brash killer T cell, the nerdy neuron, even the cute little platelets—everyone's got to come together if they want to keep you healthy!