Interstitium.

No, it’s not a Christopher Nolan sci-fi thriller. In this Science non-fiction thriller, researchers from Mount Sinai, et al describe a huge leap in our understanding of the body’s in-betweens (i.e., “interstitium”). Using the remarkable technology of confocal laser endomicroscopy, they characterize in vivo a heretofore unrecognized submucosal structure chalk full of collagen bundles. They further demonstrate this complex collagenous latticework is responsible for a whole host of contractile functions, while floating in fluid that drains into the lymph system. What’s more, this structural interstitium is present in many (or all) organ systems and likely plays a crucial part in the metastatic potential of many (or all) malignancies. They guess it hasn’t been recognized before now because, when fixed on a slide ex vivo, the fluid dries up--collapsing the latticework and fooling the observer into thinkings it's a solid structure. TBL: We’ve got a new collagenous Achilles heel to target in our fight against cancer, and confocal laser microscopy is lit. | Benias, Sci Rep 2018