NANOG and head and neck squamous cell carcinoma: In OSCC of the tongue, ALDH1+ cells with cancer stemness characteristics show decreased expression of let-7a and high expressions of NANOG and POU5F1. let-7a overexpression in ALDH1+ cells further inhibited tumor formation and metastasis in vivo, suggesting that the let-7a gene plays an important role in modulating tumorigenesis stemness of HNSCC cells [144].