Global signaling paradigms tested by the Amonlirdviman et al. model[71]. (a) Non-globally varying, constant slope within each cell, as suggested by the global signaling model depicted in Figure 5 (top). (b) Globally varying, uniform within each cell, similar to that proposed by Lawrence et al.[74]. (c) Globally varying, constant slope. This signal can be viewed as a combination of the forms shown in (a) and (b). Depending on whether the intercellular or intracellular components predominate, the slope can be in either direction. As shown, the subcellular asymmetry dominates, as in (a).