PGR and ovarian carcinoma: PR‐negative and mPR‐positive ovarian cancer cells were exposed to progesterone and seven types of PR agonists (medroxyprogesterone acetate [MPA], dehydroepiandrosterone, dienogest, levonorgestrel, drospirenone, pregnenolone, and allopregnanolone) at 10–400 μM, and viable cell counts after exposure for 30 min were measured using the water‐soluble tetrazolium (WST‐1) assay.