Figure 2.
Tumor development time and stem cell fractions depend on progeny proliferation capacity ρmax and stem cell symmetric division probability ps. The time until the tumor reaches 100,000 cells (lines) decreases with increasing ps. For small ps (ps = 10%, 25%), the stem cell fraction (columns) increases with increasing progeny proliferation capacity ρ, but for larger ps the trend reverses. For ps = 50% there is a U-shape dependence on ρmax. For ps ≤ 75%, the stem cell fraction is substantially less than the symmetric division probability ps. For ps = 50%, the average stem cell fraction in a 100,000-cell tumor is less than 5% for each ρmax.