Apart from this, the expression level of CSCs‐related proteins:CD44, ALDH1, KLF4, SOX2 and EMT‐related proteins: Slug, Vimentin were also remarkably elevated in mice SCCHN tumour than that in wild‐type normal tongue tissue (Fig. 4C). This evidence concerns the gene ALDH1A1 and head and neck squamous cell carcinoma.