So by far the most important factor, the driving force that forms the tertiary structure, is the hydrophobic effect and hydrophobic interactions. Now, that's because the majority of the proteins inside our body and inside our cells fold and create the tertiary structure in an aqueous solution, in a solution where water is the dominant solvent molecule. Now, we also have vanderballs interactions, disulfide bridges, hydrogen bonds and ionic interactions that also play a role in forming the tertiary factor. But the hydrophobic effect is that predominant force. So, as I mentioned earlier, most proteins exist in aqueous solutions and most proteins form in aqueous solutions. And what that basically means is we have the hydrophobic effect that takes place.