When pathogens invade or tumor cells emerge, the immune system is alerted by danger signals that summon a key battalion of first responders, the unsung heroes of the immune system—a population of starfish-shaped sentinels called dendritic cells.

When pathogens invade or tumor cells emerge, the immune system is alerted by danger signals that summon a key battalion of first responders, the unsung heroes of the immune system—a population of starfish-shaped sentinels called dendritic cells.