Most nuclear proteins such as transcription factors, co-activators, and RNA splicing factors are non-homogeneously distributed in the mammalian cell nucleus. They either form clusters or prominent phase separated nuclear bodies. One hypothesis is that multivalent weak protein-protein interactions mediated by low complexity domains (LCDs) play an important role in these hubs’ formation. My current goals are to develop new methodologies for characterizing the selectivity of LCD-LCD interactions and to study how these interactions may be modulated.