In vitro experiments demonstrate that glioma cell-derived Wnt3a triggers the activation of the Wnt/β-catenin pathway in microglia, induces them to express ARG-1 and STI1, shifts them to the M2 phenotype, enhances tumor infiltration, invasion, growth and the crosstalk between microglia and gliomas (87). This evidence concerns the gene ARG1 and central nervous system cancer.