Simulation examples. (A) Two time courses of individual cells (tracing of one daughter cell per division) with respect to affinity a, showing the actual cell cycle status. Black segments represent cell cycle phases G₁/G₀, gray segments indicate S/G₂/M. Whereas the upper example describes a cell maintaining/renewing a high a (ie, long-term repopulating potential), the lower example shows terminal lineage commitment after several fluctuations. (B) Corresponding cell fates represented in terms of the proposed within-tissue plasticity model⁴  (I, initiating cell; gray, S/G₂/M; black, G₁/G₀). Dormant cells in lower growth environment (gray region) regain affinity a, whereas (potentially) cycling cells in the other environment (white region) lose a.