DDX4 and sarcoma: 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.