A gene was identified within the DNA sequences of the EcoRI DNA fragme
nt N (4.3 kbp) of the genome of equine herpesvirus type 2 (EHV-2) codi
ng for a protein (179 amino acid residues) homologous to the cytokine
synthesis inhibitory factor (CSIF; interleukin 10) of the human and mo
use, and to the Epstein-Barr virus (EBV) protein BCRF1. This finding i
s further significant evidence that the interleukin 10 (IL-10) and/or
IL-10-like gene can indeed be present in the genomes of members of the
herpesviral family.