Time course of total concentrations of β-catenin and axin with transient wnt signaling. Solid line: the original Lee-Heinrich model. Other lines: kG parameter was varied. Long dashed line: kG = 0.1 min-1. Short dashed line: kG = 0.5 min-1. Dashed-dotted line: kG = 1 min-1. Dotted line: kG = 2 min-1. The other kinetic parameters of added reaction steps, kG' and kβ/kβ', were set equal to 1 and 0.1/1 min-1, respectively. The time (in minutes) to maximum β-catenin level is marked for each line.