Figure 1.

Gene expression of Nodal (A), Cripto-1 (B), and Lefty (C) in samples from highly invasive versus angiogenic phenotypes in glioblastoma xenografts developed from four (1–4) glioblastoma patient biopsies. The diagrams illustrate log₂-transformed gene expression intensity. The data were extracted from globally normalized (quantile normalization) microarray data. ArrayExpress Data Archive and corresponding patient sample codes are given in Table W1. The expression levels of Nodal, Lefty, and Cripto-1 are in the range of 0.3 to 0.7 compared to the levels of housekeeping genes such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and actin, beta (ACTB).