Figure 2.

Heatmap showing interactions between toxicants¹² and modulators (columns) that alter cytotoxicity in SH-SY5Y cells. Maximal fold-change values are shown comparing IC₅₀ value with modulator divided by IC₅₀ value without modulator. Cell sensitization to a toxicant by a modulator is indicated by a positive IC₅₀ shift value if it exceeded 3-fold increase or decrease at the highest modulator concentration that did not cause ≥10% cytotoxicity. Red fill indicates sensitization to a toxicant, with increasing color saturation from 2 to 16-fold. Blue fill indicates a negative IC₅₀ shift hence protection from a toxicant, with increasing color saturation from −2 to −16-fold. White fill indicates no interaction. 32 toxicants were tested in 10 concentrations, or with DMSO vehicle, and with 3 concentrations of each of 70 modulators. Toxicant/modulator combinations that yielded significant interactions, are colored red for increased sensitivity, blue for protection by modulator, or white for no significant interaction. The maximum fold-change shift in IC₅₀ observed is shown in each colored square.