Secondary liver cancer presents a significant challenge due to its high prevalence and lack of effective treatments. Angiotensin converting enzyme 2 (ACE2), a key enzyme of the protective arm of the renin-angiotensin system (RAS), converts angiotensin II, a pro-fibrotic and pro-carcinogenic peptide, into angiotensin (1-7), which has anti-inflammatory, antifibrotic and anti-carcinogenic properties. Our previous work established that hepatic ACE2 overexpression significantly reduce liver fibrosis. We are now extending these studies to examine its potential anti-cancer effects, with the goal of developing therapies capable of inhibiting liver fibrosis and carcinogenesis in advanced liver disease. This pilot study investigated the prophylactic effects of liver-specific ACE2 gene therapy in a secondary liver cancer model. Colon cancer cells (MC-38) were injected intrasplenically to induce secondary liver cancer in C57Bl/6 mice and a single intraperitoneal injection of ACE2 packed into a liver-specific adeno-associated viral (ACE2-AAV) vector was administered. To prevent the development of a splenic cancer burden, the mice were splenectomised 2-minutes post-MC-38 injection. As expected, ACE2 gene and protein expression was significantly (p<0.001) upregulated in cancer and non-cancer liver tissues 3-weeks post-treatment compared to healthy mice or MC-38 cell-transplanted mice receiving a control vector, human serum albumin (HSA-AAV). ACE2 therapy significantly (p<0.01) reduced secondary liver cancer burden in mice compared to control vector injected mice, as reflected by a 33% reduction in relative liver weight. Both gene and protein expression of E-cadherin was downregulated in cancer and non-cancer tissue of the liver. Importantly, ACE2 therapy significantly (p<0.05) increased E-cadherin protein levels in cancer tissues while completely restoring its level in non-cancer tissue to that of healthy liver tissues. Interestingly, CD8+ cytotoxic T cell infiltration into cancer and non-cancer tissues was significantly (p<0.05) increased by ACE2 therapy. These findings suggest that liver-targeted ACE2 therapy suppresses the growth of secondary liver cancer. The mechanisms by which ACE2 promotes cancer inhibition may include upregulation of E-cadherin protein expression and promotion of cytotoxic T cell recruitment. Therefore, we conclude that ACE2 therapy represents a promising approach for the treatment and prevention of secondary liver cancer.