Thus, in this study, we aimed to perform immunostaining to characterize the expression profiles of hypoxia-related molecules (i.e., hypoxia-inducible factor-1 subunit alpha [HIF-1α] and prostate-specific membrane antigen [PSMA]) and molecules specific to endometrial or ovarian cancer (i.e., vimentin [VIM] and aquaporin-3 [AQP3]) in these cancers because OCC is related to hypoxia.[4] Moreover, the relationship between anatomical tumor site and endometriosis was analyzed to investigate the tumor microenvironment and its relationship with tumorigenesis. This evidence concerns the gene HIF1A and endometriosis.