ARHGEF16 and glioma: Accordingly, a ChIP assay in H4 glioma cells showed that compared to normal IgG, anti-GLI2 antibody enriched the chromatin fragments containing GBS-2 or − 9, while the negative control chromatin fragment could not be enriched by the antibody (Fig. 2h), implying that GLI2 specifically bound to the ARHGEF16 promoter via both the GBS-2 and -9.