B. BALB/c mice with subcutaneous CT26 tumors were treated with vehicle, TP-16 (75 mg/kg, p.o., daily), PD-1 antibody (50 μg, i.p., twice weekly) or combined therapies for 2 weeks. Animal survival (time to tumor burden reaching 2000 mm3) was analyzed by the Kaplan-Meier method using GraphPad Prism (n=10). P values were calculated using the Log-rank test. 