CX3CR1 and cytomegalovirus infection: To explore the functional implications of paired γδ T cell subsets in CMV infection, expression levels of CD16, NKG2C, CD57, CD8, HLA-DR, CX3CR1, CD27 and CD28 were compared by γδ T cell subset between CMV-infected and CMV-uninfected groups (concatenated data) by generating superimposed histograms (Figure 7B).