Table 1. Definition of parameters used to describe the dynamics of various FFLs.

Parameter	Gene A	Gene B	Gene C	Units and remarks
mk	ma	mb	mc	M, conc. of mRNAs
pk	pa	pb	pc	M, conc. of proteins
kmk	kma	kmb	kmc	Ms−1, transcription rate
kpk	kpa	kpb	kpc	s−1, translation rate
γmk	γma	γma	γmc	s−1, decay rate constant for mRNAs
γpk	γpa	γpb	γpc	s−1, decay rate constants for proteins
mks	kma/γma	kma/γma	kma/γma	M, steady state values of mRNAs in unregulated case
pks	kpa kma/γpaγma	kpa kma/γpaγma	kpa kma/γpaγma	M, steady state values of proteins in unregulated case
Mk = mk/mks	ma/mas	ma/mas	mc/mcs	dimensionless
Pk = pk/pks	pa/pas	pb/pbs	pa/pcs	dimensionless
wk = γpc/γmk	γpc/γma	γpc/γmb	γpc/γmc	dimensionless
ρk = γpc/γpk	γpc/γpa	γpc/γpb	1	dimensionless
dzk	dza	dzb	dzc	M, total conc. of promoter
λmh	1/maswa	1/mbswc	1/mcswc	M−1, noise parameter
λph	1/pas ρa	1/pbs ρb	1/pcs ρc	M−1, noise parameter

Note: This table describes the variables and parameters used in the numerical simulations of different FFLs. Here k = a, b, c represent genes A, B and C respectively. The values d_zk represent the concentration of promoters of the gene k inside the cell. The values m_ks and p_ks are the steady-state numbers of mRNA and protein molecules associated with gene k in the absence of any type regulation.