Figure 2.

Family size distributions generated by the basic stochastic inheritance model. Panel (A) depicts the cumulative family size distribution, i.e., the percentage of naïve CD8⁺ T cells (x-axis) and the corresponding cumulative number of CD8⁺ T cells present on day 8 (y-axis). The CD8⁺ T cell families on the x-axis are ordered by their size on day 8 (with the largest family on the left). The dashed red lines represent the fraction of families that constitute 50% of the total response. Panel (B) shows the frequency distribution of family sizes on day 8, which reveals that some families contribute more than 10⁴ cells to the total response. These results are based on simulating the clonal expansion of a 1,000 naïve CD8⁺ T cells.