Validation of gene expression regulation by Immunofluorescence analysis. Indirect immunofluorescence analysis was performed on cultured human GBM tumorigenic cells PT2 (belonging to the NL-type) and PT6 (belonging to the HD-type), by using a specific antibody anti-Sema5A (green signal). Nuclei were stained by the Hoechst dye (blue signal). Merged imaged are shown. Scale bar = 20 μm.