Validation of selected genes using quantitative RT-PCR. The blue squares represent CNS/nodal sample ratios; the red inverted triangles are the CNS/extranodal sample ratios. The ratios obtained using quantitative RT-PCR are plotted along the y-axis, whereas the ratios calculated from the microarray data are plotted on the x-axis. The genes analyzed were ATP5J, BCL-6, CD10, CD44, CHI3L1, COX6B1, IRF4, SPP1, TFPI2, and GAPDH. The correlation coefficient shown is that calculated without the non-CNS outlier at the right (CHI3L1 CNS/nodal ratio). The correlation remains significant when including this outlier (R = 0.79; P < .02).