[♪ INTRO] Mr.

Frosty sounds like a frozen summer treat. But it’s also the name of a cancer-fighting gecko!

And some people would say that that’s even cooler. He got his name because of  his white and yellow coloring, a special pattern known as Lemon  Frost that is encoded in his genes. And these colors make geckos  like him very sought after.

But it turns out that his beautiful white  pigment is produced by cancerous skin cells. So scientists studied Mr. Frosty and  his family and got to the root of some questions about where skin  cancer comes from, even in humans.

Researchers at UCLA bought Mr. Frosty  from a gecko breeder to figure out how these color-producing  cells developed and evolved. And in the process, they were able to figure out some of the genes that regulate the  cancer, making those colorful skin cells.

First, they needed to know how  many genes make Lemon Frost colors. So the UCLA researchers bred Mr.  Frosty with some wild type geckos to see what their babies would look like. Wild type is the term researchers use to  describe a genetically typical animal.

About half of the babies were Lemon Frost  geckos, suggesting that Lemon Frost is the coloration of a gecko with half  wild type genes and half mutated genes. Then, those Lemon Frost baby geckos  grew up and were bred with each other. And the babies from two Lemon Frost  parents were about half Lemon Frost, about a quarter had even more white  pigment known as super Lemon Frost, and about a quarter were wild type.

That spread basically means that Lemon Frost likely comes from just one mutation  in a single segment of DNA. The researchers also figured out that  Mr. Frosty’s Lemon Frost mutation occurs on a gene that makes a ton of  white skin cells when it’s mutated.

And that’s the basic idea of some cancers. When cells aren’t properly regulated, your body keeps making more and more  of them until it becomes a problem. As you might imagine, geckos that have two copies of the mutation  develop even more tumors.

Unfortunately, that’s also  what makes them stand out with pretty colors on their skin. And here’s the thing: You have that same gene that was mutated in Mr. Frosty’s DNA.

It’s called SPINT1. Lots of animals have similar genetics, and it’s not always because  we’re directly related. Sometimes we have a common ancestor.

But other times, we both had  similar genetic mutations that allowed us to develop similar physical features. It’s called parallel evolution. And SPINT1 is a gene in humans,  as well as in other animals, that determines if you’ll develop tumors or not.

It carries the genetic code for a protein  called HAI-1, which stops growth factors. Those are the molecules that usually  direct cells to either make more of themselves or not, but HAI-1 stops  them from sending pro-growth signals. So if you have cancer cells that won’t  stop reproducing, HAI-1 is a part of the process that brings them back into check  and signals them to reproduce less.

Scientists think this is one  way that SPINT1 reduces cancer. Since HAI-1 is a product of SPINT1’s  code, a mutation that changes SPINT1’s code, like what was found in Mr. Frosty’s  DNA, could allow cancer cells to develop.

So SPINT1 is likely to be a big  player in cancer development and regulation in humans and geckos. Now, not all geckos with this genetic  mutation develop malignant skin tumors, but 80% did in the UCLA study. Which are not good odds.

See, if you have a mutation in the  SPINT1 gene, you don’t automatically get cancer, just like if you don’t have  it you’re not automatically cancer-free. One way these genes can become  more or less influential is by how often they are allowed to do their jobs. Sometimes, genes can’t produce  what they’re supposed to, because there’s something blocking  them from making proteins.

And if that happens, they end  up having less of an impact. So when SPINT1 can’t make its HAI-1 protein to help regulate the production  of cells, it can result in cancer. This is what happens to individuals  with similar cancers to Mr.

Frosty. Since the SPINT1 and HAI-1 that led  to Mr. Frosty’s cancer have also been found in humans, studying Mr.  Frosty and his descendants could help us understand where  some of our cancers come from and how to stop them from progressing.

In the end, geckos and humans might be able to help each other fight cancer together. Thanks for watching this episode of SciShow! If you enjoyed it, you might enjoy  becoming a member of our channel.

Channel members can submit  questions to our QQ inbox, or see exclusive behind-the-scenes photos. If you’re interested, you can get started by clicking the “Join” button below this video. [♪ OUTRO]