GLI1 and head and neck squamous cell carcinoma: H3K4ac modification has also been found in the promoter regions of EMT marker genes, such as CDH1 (E-cadherin), GLI1 (glioma-associated oncogene homolog 1) and SMO (smoothened homolog precursor) of the Hedgehog signaling pathway, which is involved in cancer cell migration and invasion, as shown in the head and neck squamous cell carcinoma (HNSCC) FaDu cell line [52].