|| S.B. Zimmerman, S.O. Trach Estimation of macromolecule concentrations and excluded volume effects for the cytoplasm of Escherichia coli J. Mol. Biol, 222 (1991), pp. 599-620  G. Rivas, F. Ferrone, J. Herzfeld Life in a crowded world EMBO Rep, 5 (2004), pp. 23-27 DOI: 10.1038/sj.embor.7400056PubMed ID1748995, 14710181
||P.18 left column bottom paragraph: "Protein science was revolutionized by recognizing the importance of macromolecular crowding for protein structure and function [primary source 1, refs 2, 3, 4], and by the discovery that many proteins are intrinsically disordered, i.e., they can function in the absence of fixed/unique/ordered 3D-structure [refs 5–7]. Since 5–40% of the volume of a living cell is occupied by various biological macromolecules, and since the total intracellular concentration of proteins, nucleic acids, polysaccharides, and ribonucleoproteins adds up to 80–400 mg/ml [primary sources], proteins evolve to fold and function within a highly crowded medium, with very limited available space, and considerably restricted amounts of free water [primary source 1, refs 2, 4, 9]."