KlausMosbachhasalwaysbeenamasterofsynergy.Whetherexploit-ing molecular proximity to increase reactivity, af finity interactions toimprove separations, or shape complementarity to enhance recog-nition,Klaushasdevisedcountlesswaystoamplifytheperformanceofbiomolecular systems beyondthe sum of their parts. Likewise, he hasamplifiedtheimpactofhis field(whichispartiallyofhisowncreation)through the sheer volume and brilliance of his ideas and theinspirationaleffecttheyhavehadonsomanyothers.Afewtestimonialsof his influence are provided in this tribute, and reprints of the 10articleshe publishedover the years in Biotechnology &Bioengineeringcan be found in a special Virtual Issue on the B&B website.I first met Klaus in 1985 at the Enzyme Engineering Meeting inHelsingor,Denmark(yes,we’realldatingourselveshere).Iwastheretopresent a poster, while Klaus was there to receive the EnzymeEngineeringAward.Thus,ourrolesandstaturesatthemeetingwerevastly different, but that was never evidenced by Klaus’s behaviortoward me. As with everyone, he was welcoming, gracious, andinfectiously enthusiastic (not to mention always entertaining).However,despitehismanylarger-than-lifequalities,theboldnessofhisideasneverfailedtostandout.Arevelatorythemeofhiswork–thatbiomolecules and biopolymers could be controllably modified,manipulated, and assembled together in new ways, almost likeinterchangeablepartsofsomegrandmachine–wasincrediblyexciting,andcontinuestodriveinnovationsacrossmanydifferentdisciplines.ItisaprimeexampleofKlaus’ssynergisticinfluence,andacornerstoneofhis legacy. Congratulations, Klaus, on a brilliant life and career, andthankyoufortheenrichinginfluenceyouhavehadonsomanyofus.Douglas S. ClarkEditor-in-ChiefGilbert Newton Lewis Professor, Dean of College of Chemistry,University of California, Berkeley, CA, USA