9L gliosarcoma cells expressing cel-miR-67 transfer cel-miR-67 to naïve 9L cells. Coculture of cel-miR-67–expressing 9L cells with those that expressed a luciferase reporter containing a complementary sequence to cel-miR-67 results in suppression of luciferase protein expression in the acceptor cells. This image reveals colocalization of cel-miR-67 (dark dots, in situ hybridization signal) with eGFP in 9L cells that do not express cel-miR-67. These findings indicate that glioma cells can transfer functional miRNA from one cell to another. Thus, miRNA serves as an intercellular signaling molecule in glioma. For details, see the article by Katakowski and colleagues on page 8259 of this issue.