  The concept of the molecular gene can be presented as a 4-tuple: &lt;n,l,p,c &gt;.  This analysis shows how geneticists can consistently include introns as part of a gene in one epistemic context and not in another. If the context involves identifying a gene for a primary, preprocessed RNA molecule, then the gene includes the introns as well as the exons. If the context involves identifying the gene for the resulting polypeptide, then the gene includes only the exons. Hence, in the case of DNA expression that eventually leads to the synthesis of a given polypeptide, geneticists might talk as if “the” gene included the intron (in which case they would be referring to the gene for the primary, preprocessed RNA) and yet also talk as if “the” gene excluded the introns (in which case they would be referring to the gene for the mature RNA or polypeptide). Application of the molecular gene concept is not ambiguous; in fact, it is remarkably precise provided one specifies the values for the variables in the expression “gene for linear sequence l in product p synthesized in cellular context c.”