(a) Simulation of responses to two drugs inducing either partial growth inhibition (blue) or cell death (green) in slow- and fast-growing cell lines for a 72 h assay. Colored lines correspond to the cell count over time for the maximal drug effect; black lines correspond to untreated control samples; x0 is the cell count at the time of treatment; xctrl and x(c) are the cell counts in the untreated and treated samples at the end of treatment. End-point ratios (x(c)/xctrl) are reported. (b) Simulation of the effects of a hypothetical mutation on cell division time (by row) and drug sensitivity (by column) in comparison to a reference response (center plot in gray). The untreated population is shown in black and the treated population in color based on the type of response (partial growth inhibition in blue, cytostasis in red, or cell death in green). End-point relative cell counts are reported. (c) Conventional (top) and GR-based (bottom) drug dose-response curves corresponding to the conditions in (b). Equations for each method is based on the values defined in (a). Note that the GR curves for each type of response overlap. (d) Conventional and GR-based sensitivity metrics corresponding to the dose-response curves in (c).