PMN and mast cells at early stages (5 days) of tumor development. (A) Hematoxylin and eosin (upper panel) or toluidine blue (lower panel) staining of EPI-HI or EPI-HI+CAF-HI isografts. BALB/c mice were sc inoculated with CAF-HI and/or EPI-HI cells. Original magnification: 100× Bar: 72 μm. (Insets) Magnification showing (upper panel) PMN cells or (lower panel) mast cells within the inoculation site. (B) Tumor growth of purified EPI-HI (1.5 × 104 cells) alone or admixed with CAF-HI (1.5 × 104) implanted sc in NOD/SCID mice (n = 4-5). EPI-HI or EPI-HI+CAF-HI were prepared as described in Materials and Methods. ***: p < 0.001; **: p < 0.01; *: p < 0.05. Tumor size: Mean ± s.d. (Inset) Tumor weight at the end of the experiment (day 30) for EPI-HI and EPI-HI+CAF-HI tumors.