The accumulation of reactive oxygen species during the progression of ovarian cancer [76], [77], [78], [79], [80], [81], and its effects on increased MKP3 degradation and subsequent ERK 1/2 activation [82] or the promotion of tumor angiogenesis [83] have been documented, but few studies have investigated NOX4 as a hydrogen peroxide source contributing to the development or progression of ovarian malignancies [22], [84]. This evidence concerns the gene NOX4 and ovarian cancer.