This newfound organ has been in front of doctors for years, but never really noticed until recently. A group of scientists found a space filled with fluids inside human tissue layers beneath the top lay of the skin, the lining of the gut, muscles, lungs, and blood vessels.

Photo: Jill Gregory/Mount Sinai Health System

“What we saw is this layer of the bile duct is this open fluid filled space supported by this collagen bundle latticework,” Theise, who now works at New York University School of Medicine told Reuters on Tuesday.”

The new organ in human anatomy is called interstitium.

What’s more is that it may very well be the largest organ. The pockets of fluid are surrounded by a web of collagen interwoven by a flexible protein called elastin. There could be many answers that lie in this new human organ.

New Human Organ Could Mean New Fight Against Cancer

Its main function is believed to be shock absorption to protect all moving parts. It even looks like shock absorbers.

The fluid in the organ is rich in protein and it drains directly into the lymphatic system, which is made up of a fluid filled with white blood cells that fight disease.

As such, it could be better understood how cancer spread with the interconnected fluids. But, as scientists better understand it, it could also mean that they could learn how to fight cancer too. The interstitium may slow or even prevent metastasis.