By targeting mRNA transcripts of such phages, CRISPRi-ART revealed (1) a novel intracellular, phage-generated, membrane-bound compartment during nascent stages of infection (EPI vesicle), (2) the identification and study of a phage nucleus mRNA export protein (ChmC) and (3) a selective phage nuclear protein import machinery (PicA)49–51. The gene discussed is RAE1; the disease is infection.