text: Although this term is also sometimes used interchangeably with exon, it is not the exact same thing: the exon is composed of the coding region as well as the 3 and 5 untranslated regions of the RNA, and so therefore, an exon would be partially made up of coding regions. The 3 and 5 untranslated regions of the RNA, which do not code for protein, are termed non-coding regions and are not discussed on this page.
  There is often confusion between coding regions and exomes and there is a clear distinction between these terms. While the exome refers to all exons within a genome, the coding region refers to a singular section of the DNA or RNA which specifically codes for a certain kind of protein.