Chimeric antigen receptor macrophage therapy for breast tumours mediated by targeting the tumour extracellular matrix.

The extracellular matrix (ECM) is essential for malignant tumour progression， as it is a physical barrier to various kinds of anticancer therapies. Matrix metalloproteinase (MMPs) can degrade almost all ECM components， and macrophages are an important source of MMPs. Studies using macrophages to treat tumours have shown that macrophages can enter tumour tissue to play a regulatory role.