CD34 and infection: We previously showed that culture of cord blood CD34+ HSC in the presence of cytokines known to instruct their differentiation into Langerhans cells (Strobl et al., 1997, 2018), gives rise to a population of cells capable of restricting infection progress at multiple steps of the viral replication cycle (Lauron et al., 2014; Coronel et al., 2015, 2016), thus providing an outstanding model to study the cellular determinants of CMV tropism.