where

The interior of this ring -- in general -- forms the cavity or pore where only certain substances "fit."

On top of this, there are types of macrocyclic molecular crystals where the pore only appears in the presence of certain conditions such as heat or pressure or that of other, "guest" molecules.

There is cis-decalin, where a grouping of hydrogen and carbon atoms lies on the same side of the molecule, and also trans-decalin, where the hydrogen and the carbon atoms lie on opposite sides.

"This could also apply to new terrain that forms after earthquakes or landslides where you have more or less the same situation, a mineral or rock-based substrate."

"It's these emergent viruses that we've never encountered before where IFITM3 is really the most important," Yount said.