Temporal changes in IFN γ expression following LA treatment of selected liver metastases. Groups of mice (n >5) had two tumors LA treated and tissues were collected at various time points post ablation. Control mice had sham TA performed (LA probe was not activated). Panels a and b tumor sections from control (sham ablated) and LA treated animals at day 5 post treatment respectively, stained with rat anti IFNγ monoclonal antibody. L; liver, T; tumor, N; necrotic area at the LA injury front. Panel c; temporal changes in IFNγ expression at the tumor host interface and injury front expressed as mean intensity score ± SEM. * P < 0.05 compared to sham control.