Relatedness of HRS cells to PMBL and nLPHL. (A) Top: Supervised PCA using PMBL versus nLPHL discriminating genes: the top 100 probe sets significantly up-regulated (≥ 4-fold change, FDR q-value < .05) by PMBL versus nLPHL and vice-versa, which correspond to 79 and 83 annotated genes, respectively. HRS cells of the 4 cHL histologic subtypes (mean, 2-7 samples each) are aligned based on their correlation to the first principal component, which captures most of the variance (75.6%, not shown) existing between the individual PMBL (n = 5) and nLPHL (n = 5) samples in the expression of the discriminating genes and therefore has PMBL and nLPHL at its extremes. Bottom: Heat map of the discriminating genes in the individual lymphoma samples (color code identical to Figure 1); in the first 2 NS cHLs from the top, the expression pattern of both PMBL and nLPHL genes is somewhat discordant with the other 5 NS cHLs. (B) Supervised PCA of HRS cells of the 4 histologic subtypes with respect to the PMBL versus TCRBL comparison: using the top 100 probe sets significantly up-regulated (≥ 4 fold change, FDR q-value < .05) by PMBL versus TCRBL and vice-versa, which correspond to 85 and 76 named discriminating genes, respectively. Displayed is the correlation of HRS cells from the various cHL histologic subtypes with the first principal component, accounting for 77.9% (not shown) of the total variance existing between the individual PMBL (n = 5) and TCRBL (n = 4) samples in the expression of the discriminating genes.