The long coevolution of β-herpesviruses with humans has resulted in the acquisition of a large variety of immune evasion strategies by these viruses. Presumably immune evasion genes are necessary for each herpesvirus to establish a life-long infection in their host. Human herpesvirus 7 (HHV-7) is a relatively understudied virus, likely because it does not typically pose significant health concerns. HHV-7 establishes a life-long infection in approximately 90% of the population before the age of 3 suggesting it likely possesses significant immune evasion strategies. Several genes found in a cluster near a known immune evasion gene, U21, may possibly encode novel immune evasion proteins. In an attempt to determine the function of one of these genes, U20, we previously expressed the protein in a variety of cell types. As predicted, U20 is a type I membrane protein targeted to the secretory system through a predicted N-terminal signal sequence. Interestingly, although U20 does not possess any predicted endoplasmic reticulum (ER) retention motifs, the exogenously expressed protein remained localized to the ER in all cell types examined. Here we describe a cloning project to generate constructs that will be used to examine the role of each domain (lumenal, transmembrane, or cytoplasmic) of U20 in ER retention.