have shown when all the tyrosine (Tyr) residues of protein FUS(fused in sarcoma) low-complexity region where replaced with leucine(Leu), the phase separation was inhibited.75 In addition, Brady et al. have shown that substitution of all arginine(Arg) residues with lysine (Lys) in the N-terminal low complexityregion of Ddx4 blocks phase separation.76 These pi–pi interactions, including “polarity-assisted”contacts, appear to be fundamental to the architecture of not onlysingle proteins but may also shed light on an essential role in theformation and stability of biomolecular condensates. This evidence concerns the gene FUS and sarcoma.