The cells initially recruited to the tumor have a phenotype that is consistent with an M1-like anti-tumorigenic state, however, when nuclear IL-33 is present within the glioma cell, an environment is generated that favors the reprogramming of the TAMs and potentially resident microglia to a pro-tumorigenic M2-like phenotype that in turn fuels rapid glioma growth. This evidence concerns the gene IL33 and central nervous system cancer.