Figure 2.

Cancer-free lifespan for several parameter settings. Mutation rate μ is fixed at μ = 0.00027375, because the effect of μ is described entirely by the accelerated failure time model. The number of stages, c, and the number of cells at risk, s, seem to interact. Compare for instance the change from c = 6 to c = 8 for s = 100 increasing 10-fold to s = 1000 versus the same change in c for s = 10¹⁰ increasing 10-fold to s = 10¹¹. In the first case, the original lifespan is not recovered. In the second case, the original cancer-free lifespan is more than doubled. Note that the step size for s is multiplicative, while being additive for c.