Specific miRNAs are differentially expressed in CD8+ T cell subsets. The expression levels of nine miRNAs identified by microarray analysis as being significantly differentially expressed between sorted naïve (N), central memory (CM) and effector memory (EM) T cell subsets from 3 healthy humans donors were validated in a further 3 or 4 new donors by RT-PCR. Panel (A) shows miRNAs which were up regulated and (B) shows miRNAs which were down regulated when comparing naïve to Tcm cells in microarray experiments. Each data point represents the average of triplicates from an individual donor and is expressed relative to levels in naïve cells which are set to 1. Statistical significance was analysed using GraphPad Prism software on non-normalised expression data using the Friedman test (on paired, non-parametric data) with Dunn’s multiple comparison correction applied. Results with a p value <0.05 were considered to be statistically significant. * = p <0.05; ** = p <0.01.