IL15 and neoplasm: Compared with mice in the tumor control group, intratumoral N. caninum significantly increased the levels of IL-12 (t-test, t(8) = 3.11, P = 0.014), IFN-γ (t-test, t(8) = 3.28, P = 0.011), IL-2 (t-test, t(8) = 4.62, P = 0.002), IL-10 (t-test, t(8) = 4.29, P = 0.003), and tumor necrosis factor-α (TNF-α) (t-test, t(8) = 4.98, P = 0.001) in the tumor; IL-15 was increased but not statistically significant (t-test, t(8) = 2.25, P = 0.054) (Fig. 4a).