{Reference Type}: Journal Article {Title}: Human pre-mRNA 3' end processing: reconstituting is believing. {Author}: Yoon Y;Shi Y; {Journal}: Genes Dev {Volume}: 36 {Issue}: 3 {Year}: 02 2022 1 {Factor}: 12.89 {DOI}: 10.1101/gad.349453.122 {Abstract}: It is every biochemist's dream to reconstitute a biological process in vitro using defined components, because doing so not only reduces a biological phenomenon to one or a series of biochemical reactions, but also defines the minimal list of essential components. In this issue of Genes & Development, Boreikaite and colleagues (pp. 210-224) and Schmidt and colleagues (pp. 195-209) report their independent reconstitution of human pre-mRNA 3' end processing.