Our genomes are littered with *junk* DNA known as LINE retrotransposons, which are powerful enzymes that can insert DNA into the genome. We are excited to report the structure of the LINE family member R2 and ways to engineer it for programmable gene insertion. Congratulations to @maxewilkinson, @FrangiehChris, RMacrae! @ScienceMagazine https://t.co/oMUE9v0FXi