In previous cancer-related studies, the loss of phosphatase and tensin homolog (PTEN) in melanoma cells induced by astrocytes resulted in MCP-1 oversecretion by melanoma cells, and in the recruitment of Iba1 and macrophages that reciprocally improved the outgrowth of brain metastatic tumor cells via enhanced proliferation and reduced apoptosis (17). The gene discussed is CCL2; the disease is cancer.