Chromatin immunoprecipitation assay (ChIP) of SOX2 and GLI1 followed by qPCR using different sets of primers spanning the putative BS within the selected RRs revealed co-occupancy of SOX2 and GLI1 at a distal enhancer element located at ~10 kb upstream the transcription start site (TSS) of ST3GAL1 (enhancer II), with a 3–8-fold enrichment in ST3GAL1 signal over ChIP with non-specific IgG in two different melanoma cell types (Fig. 6a–c). Here, SOX2 is linked to melanoma.