Pericytes (5×104) were cultured with GBM cells at 1:1 proportion in 96-well plates for 24-72 hours. Supernatants were collected, and TGF-β, IL-10, TNF-α and IL-6 levels were measured by sandwich ELISA with specific anti-mouse antibodies following manufacturer’s recommendations (Diaclone and Elabscience, respectively). IL-2 levels from T cell supernatants were measured in a sandwich ELISA following manufacturer’s recommendations (BD Biosciences).