Correlating consensus modules with age in the six validation data sets. Each row corresponds to a consensus co-methylation module eigengene (defined in Figure 3). The columns correspond to the age variable in each of the six validation data sets. Each cell reports correlation coefficient between the eigengene and age (top) and the corresponding P-value (bottom). Cells in the table are color coded using correlation values according to color scale on the right. All of the reported modules were significantly preserved in the Dutch WB data measured on the Illumina 450 K array (Additional file 3). The green module has a particularly strong positive correlation with age in the Dutch 450 K blood data (r = 0.56, P = 2E-8) and in the brain cloud (pre-frontal cortex) data sets (r = 0.6, P = 2E-8). The age correlations for the green module are positive in all of the data sets (most of the marginally significant P-values reflect the low sample size in the respective data sets or the low age range).