HIF1A and cervical carcinoma: Collectively, although it remains to be clarified 1) whether a hypoxia response element is present in the promoter of Tβ4, 2) which sequence in the Tβ4 promoter binds HIF-1α, and 3) the mechanism of action underlying Tβ4 expression, hypoxia-inducible NO could influence the increase in Tβ4 expression in cervical cancer cells.