RNA interference
He was a coauthor on a third fundamentally important research report showing that RNA interference could be routinely used to "knock down" the expression of major cellular proteins, work he performed with Thomas Tuschl and collaborators. A few weeks work in Weber's lab produced the highly influential paper "Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells". This paper set the stage for the widespread use of RNA interference to turn off the expression of normal genes in mammalian systems, a centrally important cell biological technique. In summary, he contributed to the development of three of the most important and routinely used lab techniques. Among his other achievements are several hundred well-cited studies concentrating mostly on the biochemistry and function of the cellular cytoskeleton.