In addition, Kim et al.’s immunohistochemical study of HIF-2α expression in 36 cases of cervical squamous cell carcinoma (CSCC) (24 radiation-sensitive and 12 radiation-resistant) showed that the fraction of HIF-2α expression in the radiation-sensitive group was lower than that in the radiation-resistant group, and that HIF-2α expression was positively correlated with radiotherapy failure or local recurrence. This evidence concerns the gene EPAS1 and skin squamous cell carcinoma.