HIF1A and head and neck squamous cell carcinoma: In addition, increased expression level of miR-21 in tumor stroma is significantly related to worsened outcome.[83] miR-31 is up-regulated in HNSCC and activates hypoxia-inducible factor-1α (HIF-1α) in normoxia and enhances the oncogenesis via factor inhibiting HIF-1(FIH).