VEGFA and ovarian serous adenocarcinoma: The high grade serous ovarian cancer cell lines HEY and OV90 cells were exposed to varying levels of oxygen (control tissue culture conditions (20%), 10%, 5%, 2.5%, 1%, and 0.2% O2) for 24 h to evaluate INHA expression and VEGFA expression (as a positive control24) by semi-quantitative RT-PCR.