**5. Future Directions**

Experimentation with MLOs is frequently focused on a few protein species. However, in vivo, the entire repertoire of macromolecules within individual biocondensates remains largely unknown. Additionally, for any given MLO, specific protein components can exhibit a broad array of PTMs, thus making it difficult to dissect which modifications are altering LLPS or perhaps serving other non-structural functional roles. Going forward, a major challenge will be to determine the precise relationship between MLOs and disease processes. For example, many human viruses encode proteins with PrLDs [90]. Given what we know about this type of protein domain, it is possible many viruses exploit LLPS during replication and infection, yet antiviral drugs do not specifically target LLPS mechanisms. In the case of neurodegenerative diseases, the pathological connections between aberrant phase transitions and neuronal death are not fully understood, and there are many non-unifying hypotheses. No drugs specifically target phase-separation processes in any neurodegenerative disease. Yet, given the almost complete lack of drugs for treating these diseases, manipulating the enzymes that regulate biocondensation may provide a new target paradigm.

**Author Contributions:** This manuscript was written by I.O. and F.S.

**Funding:** This work is supported by the National Institute of General medical Sciences (NIGMS) of the National Institutes of Health (NIH) under Award Number R35GM119790.

**Acknowledgments:** We thank Debra Yee and Hala Wyne for reviewing and editing our text.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
