Hierarchical clustering of gene expression data.

Five purified PB B cells (B1 to B5), 4 lymphoblastoid B cell lines (EBV-1, EBV-5, EBV-14, and EBV-16), 8 primary myeloma samples (MM1 to MM5 and PCL1 to PCL3), 4 MM cell lines (XG-1, XG-5, XG-6, and XG-16), and purified polyclonal plasma cells from 1 patient with reactive plasmacytosis (RP), 6 purified PPC samples (PPC1 to PPC6), and 5 normal bone marrow–derived plasma cells were studied using the Affymetrix HuGeneFL array. Each row represents a single gene and each column a single sample. The relative expression of each gene was visualized with color variation from green (weak expression) to red (high expression). Black indicates median expression.