Previous work had established that vinblastine’s natural biosynthetic pathway involves 31 steps and a large number of genes16. Building on this work, Keasling’s group edited the genome of Saccharomyces cerevisiae, introducing 34 heterologous plant genes [https://www.nature.com/articles/s41586-022-05157-3] and tweaking ten yeast genes via deletion, knock-down, or overexpression. A total of 56 genes were edited in this tour-de-force metabolic engineering project, resulting in the production of 2 vinblastine precursors, catharanthine and vindoline. These precursors were then converted to vinblastine using a final, well-established synthetic chemistry step.