Critical interactions that drive LLPS. The interactions important in LLPS include cation–π, π–π, electrostatic, and transient cross–β-contacts. Proteins that undergo LLPS are enriched for low-complexity disordered regions and multivalent domains. Polymers of ions, such as RNA, may additionally act as scaffolds or molecular seeds for LLPS. The image for transient cross–β-contacts and LARKS comes from Hughes et al. (134).