It’s CRISPR/Cas. I’m feeling a bit square because I’m not doing it yet. But maybe you’re so squaresville that you don’t even know what the heck it is. You’re saved like a hipster at a flea market: here’s a primer on CRISPR/Cas so you can pretend to be one of the with-it kids.
Simply put, this is a tool that combines targeting information that homes in on a precise location within the genome (that’s the CRISPR part), with the ability to generate DNA breaks at that site once it arrives there (that’s Cas’s job). Such tools are integral to the process of gene editing, because the ability to interrupt a continuous strand of DNA at a specific location is the first step to altering the information encoded there. There are other gene editing tools currently in use in research labs, but CRISPR/Cas has quickly gained popularity for the very practical reason that it’s a bit easier and less expensive to use than the other options.
There’s a lot more at that link, including an explanation of how CRISPR/Cas lets you edit genes. This is fast becoming one of those ubiquitous tools in molecular biology — if you don’t know how it works, you’ll be like those sad people in the 1980s who didn’t understand PCR.