a–h C57BL/6 mice were implanted subcutaneously with 1 × 106 B16F10 cells. Concentration of CDN2 in tumors (a) and plasma (b) was measured by LC-MS/MS at 5 and 30 min, 2, 6, 24, and 48 h after single IT injection (n = 3 animals per group at each time point, n = 6 animals for CDN2 (30 µg) and exoCDN2 (0.2 µg) at 5 and 30 min, 2 and 6 h). c–e Four hours after IT injection, RNAs were purified from tumors (n = 5 animals per group) and serum was collected. Relative expression of IFN-β (c), CXCL9 (d), and CXCL10 (e) genes was measured by RT-qPCR, normalized against the housekeeping gene RPS13. Serum levels of IFN-β (f), TNF-α (g), and IL-6 (h) were measured (n = 5 animals per group). Data are presented as means ± s.e.m from replicate samples as indicated. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 by one-way ANOVA with Tukey’s multiple comparison test.