Cat owners might find a glow-in-the-dark kitty to be fairly useful—you’ll never trip over the cat at night again—but the Mayo Clinic scientists who created this glowing cat had a bigger goal in mind: fighting AIDS.

The substance that makes the cat glow is a version of the green fluorescent protein that lights up the crystal jelly, a type of jellyfish that lives off the West Coast of the United States. Years ago scientists realized that the gene for GFP is a perfect marker when they insert another new gene into an organism. By inserting a version of GFP along with their gene of choice, they could easily see if they were successful because the organism would glow. Since the technique was first developed, researchers have made many glowing animals, including pigs, mice, dogs, even fish you can buy in the pet store.

In this latest bit of research, published in Nature Methods, the Mayo Clinic scientists inserted a version of the GFP gene along with a gene from the rhesus macaque that blocks the feline immunodeficiency virus (FIV)—the virus that causes feline AIDS—into the unfertilized eggs of a cat. After those eggs were fertilized, they produced kitties that glowed green, showing that they also had the anti-FIV gene. Even better, subsequent generations of cats also glowed and had the anti-FIV gene.

The researchers still have more work to do to determine whether the anti-FIV gene works in the cats. “We haven’t shown cats that are AIDS-proof,” study co-author Eric Poeschla told LiveScience. “We still have to do infection studies involving whole cats. That the protection gene is expressed in the cat lymphoid organs, where AIDS virus spread and cell death mostly play out, is encouraging to us, however.”

The ultimate goal of this line of research, though, is to figure out how to make humans resistant to HIV, the virus that causes human AIDS. “We want to see if we can protect the domestic cat against its AIDS virus, if we can protect any species, eventually including ours, against its own AIDS virus,” Poeschla told LiveScience.