Teams led by Graham Hatfull and collaborators constructed bacteriophages with fully synthetic genomes, creating a platform that allows researchers to add, remove and edit genes modularly. The method enables systematic dissection of phage biology and the engineering of therapeutic phages with defined functions. Authors reported that synthetic‑genome phages support targeted gene replacements and combinatorial edits, accelerating functional studies and translational efforts against bacterial pathogens. The work opens new avenues for precision phage therapy development and for using synthetic virology to probe host–virus interactions.