How meningeal macrophages control medulloblastoma induction.

In this issue of Developmental Cell, Pokrajac et al. report that Wnt signaling in endothelial cells maintain CXCL4 expression in meningeal macrophages, which suppresses induction of Sonic hedgehog medulloblastoma by antagonizing the pro-tumor effects of CXCL12. This work highlights how homeostatic tissue macrophages can regulate early stages of tumor induction.