FIGURE 1.

Combined expression of ABC transporter genes predicts cumulative survival in 251 patients with neuroblastoma. A, k-Means cluster analysis of ABC genes in primary neuroblastoma tumors. Expression profiles of 15 ABC transporter genes demonstrating prognostic significance following survival analysis in 251 primary neuroblastoma tumors were clustered into three groups using the Cluster 3 program and unsupervised k-means clustering. The rows represent the genes (indicated on the right side), whereas the columns represent patient samples. The levels of gene expression as log values are shown ranging from green (−1.0) to red (1.0). The red bars above the samples indicate those tumors displaying MYCN amplification. B, Kaplan-Meier survival analysis of these clusters revealed that the gene expression signature of the patients in Cluster 1 correlated with a significantly increased risk of death when compared with Cluster 2 or 3 (p < 0.0001).