Additional file 5 of DNA methylation profiles of bronchoscopic biopsies for the diagnosis of lung cancer

Additional file 5. Fig. S4: Correlation matrix of DNA methylation data collected from 40 surgical tumor specimens and their corresponding control using the HumanMethylation450 BeadChip. DNA methylation data of all surgical specimens included into this study were subjected to correlation analysis by first calculating Pearson’s correlation coefficient for each combination of sample pairs and subsequently building a correlation matrix. Red bar below and right of the matrix: tumor samples, green bar: controls. Matrix and bar below of the matrix: blue: low correlation coefficient, yellow high correlation coefficient. While control samples are characterized by high homogeneity of their methylation values, the tumor methylome is highly heterogeneous.