Unsupervised hierarchical clustering of MCL patients showed 3 distinct MCL clusters. (A) Significant differences in the PS among the 3 groups (P = .01 by Kruskal-Wallis test). PS included the same gene set identified in Rosenwald et al.¹⁹  (B) Differential miRNA expression (95 miRNAs, P < .005) among these clusters designated as cluster A (associated with high PS), cluster B (medium PS), and cluster C (low PS). (C) Differential gene expression (649 transcripts, P < .005) among the 3 clusters, with cluster A showing high expression of proliferation-associated genes and the other clusters showing higher expression of genes associated with stromal components.