Scientists have been recording data in DNA for a while, but it has usually involved bacteria and other simple organisms. MIT, however, just took a big leap forward. Its researchers have used the CRISPR gene editing technique to record histories in human cell DNA for the first time. They've crafted a gene circuit that only expresses an enzyme when it's near a key immune cell molecule, building up mutations the more it's exposed to that molecule. All you have to do to extract "memories" is to sequence those genes. They'll tell you whether or not there was a lot of inflammation, for instance.