Viral epitranscriptomics is the field that studies RNA modifications in viral transcripts that do not affect the sequence of the transcript but that are functionally relevant. So far, the studies have been focused on viral transcripts of mammalian viruses. Mammalian viral transcripts must function in a mammalian cell, so they must acquire the same epigenetic marks as the host cell. For this, viruses make use of the numerous mRNA modifying enzymes found in the host cells.