HSF1 expression was diminished in MCF10A cells for 48 hours using siRNA prior to treatment with either DMSO or RSL3 at the range of concentrations shown. Cells were assessed for viability after 24 hours. Absorbance was normalized to DMSO control. Shown are three independent replicates with standard deviation (n=3 experiments per group). P‑values were obtained by unpaired Student's t‑test with *P<0.05, **p<0.01, ***p<0.005. Exact p‑values are reported in the Appendix Table S1. 