Hence, expression of IL-10 by TAMs in glioma tissue appears to be an important immunosuppressive mediator of the glioma microenvironment, and its concomitant expression in glioma cells may serve both as an initial chemotactic agent to recruit monocytes, as well as the driver of feedforward loops of immunosuppressive mediator expression between tumor cells and macrophages within the tumor microenvironment [29, 34]. This evidence concerns the gene IL10 and central nervous system cancer.