Platelet microRNA profiling in 19 healthy subjects. (A) Unsupervised hierarchical clustering of miRNA expression profiles. The dendrogram was generated with 284 miRBase miRNAs that were expressed in the platelets of all 19 subjects included in the study. The dendrogram represents a Euclidean distance dendrogram of the median-centered log ratio values for the 19 samples. Two major clusters are identified, which tend to differentiate between platelets of differing reactivity to epinephrine. (B) Heatmap with miRNAs that were differentially expressed between the 2 platelet reactivity groups using a 2-sample unequal variances t test. Each row in the heatmap indicates the log-ratio intensity data of 1 DE miRNA across the 19 subjects.