Fig. 1.

Plasmodium infection inhibited tumor progression and prolonged survival in tumor-bearing mice. a-d C57BL/6 mice were simultaneously administered a s.c. injection of Hepa1–6 (a, b) or H22 (c, d) cells and an i.p. injection of Plasmodium parasites (n = 12). The tumor sizes and survival of the mice were monitored. The data are representative of three independent experiments. The columns present the means ± SDs. The statistical analysis was performed using GraphPad Prism software 6.0 (two-way analysis of variance (ANOVA)). **, p < 0.01; ***, p < 0.001. e-f Hepa1–6 cells were injected into the livers of mice, and parasites were inoculated via the i.p. route (n = 10). Seventeen days later, the liver, spleen, and orthotopic tumor (black arrow) were removed and photographed (e). The nodules (black arrow) in the liver were observed by H&E staining and imaged (f, left panel). Original magnification: 400×. The number of nodules was counted under the same original magnification (200×) for quantitative analysis (f, right panel)