Table 1. Physiological variables used as proxy for performance in signal transduction circuit.

Variables	Circuit performance improves witha	Experimental support
Signal amplification	Higher amplification	(Alves & Savageau, 2003; Kærn et al., 2005; Igoshin, Alves & Savageau, 2008; Kuchina et al., 2011; Salvado et al., 2012; Espinar et al., 2013; Berens et al., 2017)
Noise attenuationb	Attenuated noise	(Kærn et al., 2005; Kaufmann & Van Oudenaarden, 2007; Raj & Van Oudenaarden, 2008; Tiwari & Igoshin, 2012)
Information transmissionb	Higher transmission	(Kærn et al., 2005; Kaufmann & Van Oudenaarden, 2007; Raj & Van Oudenaarden, 2008; Tiwari & Igoshin, 2012)
Robustness to changes in parameter values	High robustness (low sensitivity)	(Alves & Savageau, 2003; Igoshin, Alves & Savageau, 2008; Cağatay et al., 2009; Salvado et al., 2012; Berens et al., 2017)
Speed of response to changes	Rate of adaptation	(Alves & Savageau, 2003; Igoshin, Alves & Savageau, 2008; Kuchina et al., 2011; Cheong et al., 2011; Salvado et al., 2012; Narula et al., 2015; Shimell et al., 2018)
Metabolic cost of circuit	Low cost	(Noor et al., 2016; Pereira et al., 2018)

Notes.

^aAs a general trend.

^bRelevant in the stochastic domains of dynamic behavior.