EGF and glioblastoma: First, to examine the sensitivity of our GBM cell lines to SHH, we exposed dissociated control and dnKif3a-expressing/cilia-ablated L0, S2, and S3 cells to vehicle or recombinant human SHH (1 μg/ml) in growth media in the absence of bFGF, EGF, and serum for five days and assessed the levels of cell proliferation.