In vivo visualization of immunosuppressive cells in the tumor microenvironment

Immunosuppressive cells are pivotal players in tumor progression by affecting the efficacy of conventional therapies and the prognosis of cancer patients. Visualization and real-time evaluation of these cells are very important to achieve patient-oriented precision oncological medicine. Noninvasive imaging techniques are excellent tools for this purpose, and various molecular imaging probes have been developed to monitor these protumoral immunosuppressive cells in the tumor microenvironment. In this review, we provide a brief update on the biology of immunosuppressive cells and outline recent progress in their visualization.