MARCO promotes cholangiocarcinogenesis by inducing immunosuppression and its targeting reduces tumor growth.

mice exhibited lower levels of immunosuppressive markers on macrophages and cytotoxic T cells, resulting in improved overall survival and reduced lung metastases in an orthotopic tumor model. The use of an anti-MARCO antibody further reduced tumor volume in wild-type mice. This study identifies MARCO as a key regulator of immunosuppression, fibrosis and tumor progression in iCCA, and supports its potential as a novel therapeutic target for macrophage-directed immunotherapy.