Nanobodies are highly attractive to promote better active nanocarrier targeting, while M2-TAMs (tumor-associated macrophages) dominate the tumor microenvironment (TME) resulting in a worse treatment of breast cancer. Hence, there is a clear need to develop novel strategies to perturb TAM equilibrium. This project will use GPNMB/CD206-targeted nanobodies and nanoparticles to reveal the specific pathways for M2-TAMs re-education.