Expected and observed bootstrapped mean mutation load distributions in ART and unaltered RT regions, indicating the timing of ART occurrence relative to mutation accumulation in the most recent common ancestor (MRCA). Upper plots: Expected patterns illustrating how the relative timing of ART should be captured by the number of mutations occurring before or after ART. The distribution in Early N -to-Late T regions is expected to be the same as in Late N+T regions when all mutations in the MRCA are accumulated after ART while the distribution is expected to move closer to the distribution in Early N+T regions when more mutations are accumulated before ART. Lower plots: Observed distributions of mean mutation load values in different altered and unaltered RT regions per cancer type and their estimated ART timing relative to the mutation accumulation in their MRCA. Middle plot: Bars represent percentages of mutations accumulated prior to ART with percentages from the upper plots highlighted in grey.
