Figure 1. (A) Antitumor activity of metronomic cyclophosphamide, single low-dose cyclophosphamide, AdIL-12 and their combinations in the CT26 colorectal carcinoma model. Animals were distributed into different groups: saline; metronomic cyclophosphamide (Cy Me, 25 mg/kg i.p., 3 times/week, from day 8); single low-dose cyclophosphamide (Cy Mo, 50 mg/kg i.p., day 8); AdIL-12 (10⁹ TCID₅₀ i.t., day 9); Cy Me + AdIL-12 and Cy Mo + AdIL-12. Data are expressed as mean (bars = SEM) tumor volume. From day 20 onward: Cy Me + AdIL-12 vs. Cy Mo + AdIL-12 p < 0.05. Student's t-test was used to compare tumor sizes among different groups. (B) Antitumor activity of Cy Me + AdIL-12 and Cy Mo + AdIL-12; each line represents one individual tumor. (C) Percentage of complete tumor regressions (CR). (D) Animal survival analysis. Kaplan-Meier, log rank test, *** p < 0.001: saline vs. Cy Me + AdIL-12; +++ p < 0.001: AdIL-12 vs. Cy Me + AdIL-12; ## p < 0.01: Cy Me vs. Cy Me + AdL-12; σσσ p < 0.01: Cy Mo + AdL-12 vs. Cy Me + AdL-12.