Generally, immunoreactivity for HIF-1α was detected with intense cytoplasmatic and nuclear positivity in tumor cells of cases with positive HPV16 DNA (Group II) (Figure 1C), whereas a weak cytoplasmatic expression was found in tumor cells of the non-infected group (Group I) (Figure 1D), similar to the one found in some of the islet of precancerous squamous epithelium adjacent to the infected positive HPV16 DNA tumors (Group II). Here, HIF1A is linked to neoplasm.