A coin struck by Brutus in 43/2 B.C.E. refers to his assassination of Caesar. On one side is the head of Brutus and on the other is the symbol of two daggers and a helmet, with the inscription "Eid Mar" (the Ides of March是恺撒被暗杀的日子，Ides指古罗马历中3月,5月,7月,10月的第15日,其余各月份的第13日).

    免疫系统有保护和破坏两个方面，科学家们正在努力探索新方法，目的是利用这两个方面来治疗感染、癌症和自体免疫性疾病。本期的专题部分有三篇“观点”文章、两篇“综述”和一组特别的新闻报道展望了免疫治疗研究的进展，包括仍在实验室中的测试的概念和其它已经到了临床试验阶段的概念。本期的封面与这个专题有关。

    Two Sides of a Coin

    When Brutus and his conspirators plotted to assassinate Julius Caesar on 15 March 44 B.C.E., they considered it an act of loyalty to the republic; yet at the same time it was a betrayal of the leader they had sworn to protect. The immune system also presents two faces: On the one hand, it works to protect us by fighting infection and malignancy; while on the other, it can prove treacherous, attacking tissues and cells of the body to produce debilitating and even fatal autoimmune diseases. ......