CD27 and Huntington disease: Based on prior studies (Alanio et al., 2010; De Rosa et al., 2001) and our confirmatory experiments using 5 phenotypic markers for naïve or memory T cells, we determined that co-expression of high levels of CD45RA and CD27 were sufficient to classify naïve T cells in both HD and cHCV patients (Figure 1—figure supplement 3).