LAT and disease arising from reactivation of latent virus: In HSV-1, its LAT is also expressed during acute and latent infection, and viruses lacking LAT do not establish latency as efficiently as wild-type HSV-1 and exhibit delayed reactivation [16,17,18], suggesting that the LAT is involved in HSV-1 latency establishment and facilitates HSV-1 reactivation from latency.