Table 1. Cellular processes in the airway epithelium model.

Qk	Process	Δk i1	Δk i2	Δk i3
Q1	Differentiation of SCs into SecrCs by symmetric divisions	-1	2	0
Q2	Differentiation of SCs into CilCs by symmetric divisions	-1	0	2
Q3	Symmetric self-renewal of SCs	1	0	0
Q4	Differentiation of SecrCs into CilCs by symmetric divisions	0	-1	2
Q5	Symmetric self-renewal of SecrCs	0	1	0
Q6	De-differentiation of SecrCs	1	-1	0
Q7	Death of SecrCs	0	-1	0
Q8	Death of CilCs	0	0	-1
Q9	Asymmetric divisions of SCs producing one SecrC offspring	0	1	0
Q10	Asymmetric divisions of SCs producing one CilC offspring	0	0	1
Q11	Asymmetric divisions of SecrCs producing one CilC offspring	0	0	1

A description of the processes depicted in Fig 1. Although processes Q₅ and Q₉, Q₁₀ and Q₁₁ are equivalent from the viewpoint of cellular population change, we count them as different processes, because they can be regulated differently.