An immunologist and a cardiologist are kidnapped. The kidnappers threaten to shoot one of them, but promise to spare whoever has made the greater contribution to humanity. The cardiologist says, āWell, Iāve identified drugs that have saved the lives of millions of people.ā Impressed, the kidnappers turn to the immunologist. āWhat have you done?ā they ask. The immunologist says, āThe thing is, the immune system is very complicated ā¦ā And the cardiologist says, āJust shoot me now.ā