 This led to deep insights into RAS function, eventually solving the RAS biochemical pathway in yeasts and humans, and demonstrating the multifunctional nature of this important oncogene.From this work in fungi new cellular mechanisms were recognized for "insulating" signal transduction pathways with protein scaffolds that reduce cross-talk and for processing and localization of proteins.During this period Wigler's lab published the first use of epitope tagging for protein purification.