Estimated expression levels and error in estimation. For each gene of the SOS system, we have superimposed the estimated expression levels on measured expression levels and plotted the error in estimation in a separate panel. We have done this for the low radiation level data set in Figure 4. The estimations generally show good behaviors. Figs. 4a, 4b, 4c, 4d, 4e, 4f, 4g are for the low radiation level data set, and plotted genes lexA, polB, umuD, uvrD, uvrA, uvrY, and ruvA, respectively. Each gene has two plots; the bottom panel shows estimated expression level superimposed on measured expression level, while the top panel is the estimation error.