CD38 and cytomegalovirus infection: Because a CD28−CD27−CD127− phenotype was previously described to be a result of ongoing antigen-stimulation, as found in latent CMV infection, we next determined the expression of activation markers, such as of KLRG-1, CD69, CD38 and CD25 on Gn465–473 and Influenza A-specific T cells within the seven HLA-B*3501+ ANDV-convalescent (Fig. 6D).