Upon exposure to C6 glioma cells originating stimuli, BV2 microglia acquire a tumour-supportive phenotype, as demonstrated by their ability to enhance the migration capability of the cancer cells evaluated using a transwell migration assay (Fig. 1A), as well as the expression of genes (Il1β, Mmp9, Vegfb and Tgfb1) and secretion of proteins (IL18, TGFB1) associated to a microglial tumour-supportive phenotype (Fig. 1B, C). The gene discussed is MMP9; the disease is central nervous system cancer.