PGR and adenomyosis: Studies have found that sex hormone anomalies including local hyper-estrogenism due to the activation of aromatase and sulfatase, decreased progesterone receptors, progesterone resistance, inflammation, altered cell proliferation, and neuro-angiogenesis are likely key pathogenic mechanisms of pain, abnormal uterine bleeding (AUB), and infertility in adenomyosis [1,31].