result from differences in genetic or environmental fac-tors, differences in disease stage, or any of many otherfactors.A breakthrough was achieved from proﬁling genetranscription in malignant cells from 40 patients, withthe use of microarray technology (Figure 17-23). In this study, two different patterns of gene expressionwere observed. One pattern, called the germinal-centerB-cell-like pattern (GCB), correlates with a muchhigher probability of patient survival after standardchemotherapy than does the other pattern, called acti-vated B-cell-like DLBCL. (These patterns are named fortheir similarities in gene expression to certain normalB-lymphocyte cell types.) This ﬁnding suggests thateven though DLBCL is diagnosed histologically as onedisease, at a molecular level it is more like two differentdiseases. This result raises the hope of more accuratediagnosis and of treatment that can be focused speciﬁ-cally on each disease. Further, such microarray experi-
This is the end of the preview. Sign up
access the rest of the document.