Cells are highly organized structures. In addition to membrane delimited 
organelles, proteins and RNAs can organize themselves into specific domains. 
Some examples include stress granules and subnuclear bodies. This level of 
organization is essential for the correct execution of multiple processes in the 
cell, ranging from cell signaling to assembly of structures such as the 
ribosomes. Here we will review evidence that noncoding RNAs play a critical role 
in the establishment and regulation of these domains. The unique abilities of 
RNA to mark the genome in a gene-specific and condition-specific manner and to 
serve as tethers nominate them as ideal molecular address codes.