MCB aspires to evolve as new discoveries are made in molecular and cellular biology. Over the past few years, nucleocytoplasmic transport has been shown to play a key role in virtually all areas where MCB has traditionally been strong. These areas include transcriptional regulation, signal transduction, cell cycle control, DNA replication and recombination, and RNA processing. Moreover, molecular analysis of the signals, pathways, and machinery required for nuclear transport is now moving rapidly, and we are only beginning to appreciate the full impact of the dynamic nucleocytoplasmic exchange of macromolecules. MCB already receives many submissions in this area, but we encourage more. To highlight the importance of this emerging area, we are establishing a new section of the journal entitled Nucleocytoplasmic Communication. Our hope is that this new section will provide a home for important findings in nucleocytoplasmic transport that transcend the traditional boundaries between research areas.