Non-protein-coding DNA sequences that are interspersed within genes are called introns.  Introns are transcribed into mRNA along with coding sequences, but must be removed before the mRNA can be used for protein synthesis.

The newly coined term exome refers to the protein-coding DNA sequences of the genome.  The exome constitutes about  1.5% of the human genome.  Because the exome contains all the protein information about the genome, it is considered the most important and most interpretable part of the genome.  Whereas 3 billion bases must be sequenced to yield a complete genome sequence, only about 45 million bases need to be sequenced to yield a person's exome.