Fig 3. Illustration of a two-checkpoint drift-diffusion+threshold model of the cell cycle.

Simulation was performed by numerically solving Eq 1, twice in sequence, using the Euler-Maruyama algorithm [56] with a fixed time step Δt = 0.01. Drift and diffusion constants are μ₁ = μ₂ = 0.2 and σ₁ = σ₂ = 0.1, respectively.