ITGB5 and glioblastoma: To examine the functions of ITGB5 in GBM in greater detail, we used two ITGB5-specific siRNAs to knock down ITGB5 expression in a stable glioma cell line (LN229) and a primary glioma cell line derived from a clinical GBM specimen (PGC1228) (Figure 5A; Figure S4).