MCF7 breast cancer cells alone or mixed with WT or Hsf1 null primary MEFs were injected subcutaneously into NOD-scid mice. The experiment was repeated twice, with 4 mice per group in each experiment. (A) The mean tumor volume (total 8 per treatment group) is shown. The distribution of individual measurements is shown in the lower panels, in scatter plots for days 22 and 38 post injection. Error bars, SEM. *p<0.05, **p<0.01. (B) Mice were sacrificed when tumor burden reached size limit and the tumors were excised, fixed and stained with hematoxylin & eosin (H&E, upper panels) or Masson’s trichrome stain (lower panels). All images collected at the same magnification. Scale bar = 50μm. See also Figure S2.