Protein folding, misfolding, and un/non-folding: overview of the SP16 Session at the 20th IUPAB congress, 45th Annual Meeting of SBBf, and 50th Annual Meeting of SBBq.

The classical and idealistic consideration of the protein universe as a set of well-ordered proteinaceous machines with unique spatial organizations conducting unique biological functions is changed because of the recognition that proteins can fold, misfold, or be disordered to different degree. Functional repertoires of intrinsically disordered proteins complement functions of ordered proteins, whereas protein misfolding and concomitant oligomerization, aggregation, and fibrillation are related to the pathogenesis of numerous human diseases. Flexible proteins can undergo liquid-liquid phase separation, which is at the heart of the biogenesis of numerous membrane-less organelles. Many of these aspects were highlighted in four talks delivered at the SP16 Session at the 20th IUPAB congress, 45th Annual Meeting of SBBf, and 50th Annual Meeting of SBBq. © International Union for Pure and Applied Biophysics (IUPAB) and Springer-Verlag GmbH Germany, part of Springer Nature 2021.