Heatmap representation and counts of all possible comparisons between sets of overlapping sequences within the database. Counts of possible comparisons were generated using 2 custom Perl scripts and SQL statements, then visualized as a heatmap using R. A. Number of patients for which within-patient comparisons across tissue-types can be made. For pairs of tissues from the X and Y-axis, numbers indicate the number of patients for which overlapping sequences from both tissues are available. For example, there are 11 patients with overlapping sequences from both Frontal lobe and Temporal lobe. B. Number of possible pair-wise comparisons across patients within each tissue type. For each tissue on the Y-axis, numbers indicate the count of possible pair-wise comparisons between patients. For example, there are 2 patients with overlapping sequences from White matter of neuroaxis, giving 1 possible comparison, and 4 patients with overlapping sequence from Left occipital lobe, giving 6 possible pair-wise comparisons. Tissue definitions are ontologically inclusive, i.e. Frontal lobe also includes White matter of frontal lobe, Cortex of frontal lobe, etc. Cells are colored as a heat map accentuating high values, and range from light yellow (low values) to dark red (high values). Black indicates no comparisons possible.