HHV (Human Herpesviruses) is a group of DNA viruses, including HHV-1 to HHV-8. These viruses have a double-stranded DNA and enveloped structure, localized in the nucleus of host cells. HHV regulates cell growth, differentiation, and immune responses, with latent infections associated with various biological reactions and signaling pathways. Gene expression of HHV is tissue-specific, and mutations can lead to changes in viral virulence or increased drug resistance.