Examples of distributions of intra-tumor MAFs and their relation to MATH values.

<p>Density plots (smoothed histograms) of the distributions of MAFs for two HNSCCs. The horizontal-axis position of each circle represents the MAF for a tumor-specific mutated locus in the indicated tumor sample, for loci having MAFs no lower than 0.075: left, 117 loci; right, 106 loci. For each tumor, the median and the MAD of its MAFs are indicated; each tumor MATH value is the percentage ratio of its MAD to its median. The vertical density axis is scaled so that the area under the smoothed curve equals 1; a high peak density value indicates a sharp peak. MAFs of mutated loci in the high-heterogeneity tumor (right panel) show a lower median and higher MAD than those in the low-heterogeneity tumor (left panel), even though the total numbers of mutated loci, a measure of mutation rates within the tumors, are similar.