Fig. 4.

Model for a homeostasis mutant. a Wild-type. b. Homeostasis mutant. The size-dependence of gene expression for both activators and inhibitors has been decreased, so the slopes of activity vs size are now flatter than WT. There is a greater region of stochastic overlap, so size variability is larger. Any mutant causing a flattening of either slope (i.e., activators or inhibitors) will be a homeostasis mutant