Extended Data Fig. 7: Comparing primary tumor clonal frequencies with clonal prevalence in CTC clusters, evaluating the expected versus observed fraction of oligoclonal CTC clusters.

a, Plot showing the mean clonal frequencies of barcodes in primary tumor and CTC clusters stratified by primary tumor abundance (‘high’ for clones within the 99.9 percentile of the empirical distribution of its relative abundances in primary tumors, and ‘low’ for clones outside the 99.9 percentile). Bootstrapping (sample size = 1,000) addresses uncertainty in the estimate. The centers of the boxplots are defined as the medians of the estimates, top and bottom hinges show the first and third quartiles, respectively, and whiskers reach out to the furthest points whose distance from the hinges is smaller than 1.5 times the interquartile range. All outliers are plotted as points. The distortion of clonal representation in CTC clusters is significant (combined one-sided, ***P < 1 × 10⁻¹⁵, χ² = 3,992.58 with 852 degrees of freedom; Supplementary Note 3). b, Heatmap illustrating the inferred fraction of monoclonality among CTC clusters, stratified by CTC cluster size (x axis, depicted are CTC clusters with two to five cells) and mouse sample (y axis). P values (one-sided) represent significance levels for the deviation from expected monoclonality levels by random clonal mixing (Supplementary Note 4). P values at the margins represent the combined P values obtained by Fisher’s method. NA, not applicable.