Figure 4.

Verification of 6-gene signature. A. PCA of the six NB associated genes ALK, BIRC5, CCND1, MYCN, NTRK1, and PHOX2B on three data sets: De Preter (left panel), McArdle/Wilzén (middle panel), and Wang (right panel). Samples (spheres) in the two test data sets (De Preter and McArdle/Wilzén) are coloured by the PCA clusters: Green = p1, Orange = p2, Red = p3, and Blue = p4. Samples (spheres) in the Wang data set are coloured by the hierarchical subgroups: Green = h1, Orange = h2, Blue = h4, and Red = h3, Grey = Human fetal brain. Human fetal brain (marked with an arrow) is distinct from the 101 NB samples. B. Expression heat map of the 6-gene signature of the Wang data set. The colour scale is based on standard deviations (SD) and ranges from +2 SD (red) to -2 SD (green). Samples are presented in the same order as in Figure 3A.