Heat map derived from the GCTOF MS metabolomics dataset comparing 289 tumor samples and 15 normal samples. Metabolites are plotted on the y-axis and samples on the x-axis. Data were log2-transformed and median centered in a metabolite-wise manner. Blue indicates data points with a value smaller than the median of the respective metabolite and red indicates higher values. The hierarchical clustering reveals that the measured metabolites can separate normal and cancer tissues. Only two cancer samples cluster together with the normal samples, and one normal sample behaves as an outlier.