Figure 4

Multi-way glioma data set: Characteristics of oligodendrogliomas are linked to modifications of the genomic status of genes located on 1p and 19q positions. The Variables Representation is displayed and the genes that are the most correlated to each principal components (ten positively and ten negatively) are named. Each genes of the two groups (CGH, red and eX, green) are projected on the factor map and represented as a vector. This scatter plot is read as in PCA. The more a vector has a magnitude close to 1, the best the projection is. The vector points in the direction of the high values, e.g. in our case, a gene from eX corresponding to a vector pointing in the right side is over expressed in oligodendroglioma compared to glioblastoma. The examination of the genes linked to PC2 underlines modifications of the genomic status of genes located on 1p and 19q positions (see Table 1).