PDF file - 22K, Figure S1. Glioma cells induce B7-H1 expression in peripheral monocytes from healthy donors. Monocytes from healthy donors were cultured alone in normal media or in co-culture with U251 glioma cells in contact or through a 0.2μm pore filter. The percentage of B7-H1 expressing cells was determined by flow cytometry. Compared to normal monocytes, cells cultured with glioma cells through a filter (non-contact) have significantly more B7-H1 positive monocytes (* p < 0.005) and cells co-cultured in contact demonstrate a further significant increase in B7-H1 expression (vs. normal, ** p