Infection of CD34+ HPCs with TB40E-GFP-US28-R129A results in prereactivation and reactivation levels of virus comparable to those observed for WT-infected HPCs (Fig. 5), suggesting that a lack of US28 constitutive signaling does not alter the ability of the virus to establish and maintain latency or reactivate, which contrasts with recent findings using a monocyte/THP-1 system (15). Here, CD34 is linked to infection.