Normal B-cell miRNA expression signature in DLBCL. Unsupervised hierarchical clustering analysis of 21 DLBCL with 39 miRNA genes related to normal B cells recapitulated the subsets defined by the DLBCL-relevant miRNAs in the most of the samples; except for 2 tumors originally assigned to MG-A and MG-C and now branching from MG-B. However, the malignant transformation process also disrupted the coordinated miRNA expression of normal B cells as illustrated by a mix of miRNAs related to centroblast (light blue), noncentroblast (memory/naive; dark blue), and memory cells (green) clustering in MG-B and MG-C. MG-A was primarily composed of centroblast-related miRNAs, although miR-671 (memory cells) was also clustered with this group.