<p>To assess the uncertainty in hierarchical cluster analysis over samples, bootstrap resampling (10,000 iterations) was applied via the R package Pvclust <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002936#pcbi.1002936-Suzuki1" target="_blank">[26]</a>. The uncentered Pearson correlation is used as the distance metric with average linkage. The numbers above each edge show the probability of nodes below that edge occurring as a cluster in resampled trees, via ordinary bootstrap resampling (BP, green) or multiscale bootstrap resampling (AU, red). See <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002936#s4" target="_blank">Materials and Methods</a> for details on bootstrapping.</p