Dear Editor,rnEquine infectious anemia virus (EIAV) belongs to the macrophage-tropic lentiviruses family and infects mainly equines,including horses,donkeys and mules.EIAV shares many similar characteristics in its viral biology and hostvirus immune regulation with other lentiviruses,such as human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV),and has been accepted as a model for the study of other lentiviruses,especially HIV-1 (Craigo and Montelaro 2013).