The animal world is pretty cool and it is full of some very interesting facts that make you really marvel at what it is capable of doing. Look at the shark and the ray as a prime example because they are the only two animals that we know about that do not get cancer in any way.
It is shocking to think that every other living thing can, in theory, develop cancer so it then begs the question as to why a shark or a ray is seen as being rather special in avoiding this horrible disease.
It appears to be the case that they do not get it because they have no bones in their body. Instead, they have cartilage and scientists have only been able to effectively guess that this may very well be the reason as to why they end up being cancer free. Of course, this is simply the only explanation that they can come up with at this moment in time, so there is no guarantee that they will be correct.