All studies were approved by the institutional animal care and use committee (IACUC). The N1S1 orthotopic HCC model was developed as previously described (n = 8) [41 (link)]. Rats were randomized to ultrasound (US)-guided partial laser ablation (n = 5) or sham laser ablation (n = 3) using methods previously described [41 (link)]. Briefly, all ablation experiments were performed using an US Food and Drug Administration-approved 980-nm laser generator (Visualase, Houston, TX). Under ultrasound guidance with an L8-18i transducer (logiq E9 Ultrasound, GE Healthcare), a bare 400-μm core optical laser fiber with a 1.0-cm diffusing tip was percutaneously inserted through a 22-gauge introducer sheath at the tumor margin, and a 22-gauge needle with a 25-gauge wire thermocouple (Valleylab, Boulder, CO) was inserted 4–5 mm from the laser fiber tip within the tumor for intraprocedural temperature monitoring. For the ablation group, tumors were ablated at a power setting of 3 W under continuous US monitoring, and the ablation stopped when the thermocouple reached 45 °C in order to generate an intentional partial ablation. The laser was not turned on for sham-ablated animals. Rats were euthanized by CO2 inhalation 24 h after laser or sham ablation.