NPR2 and polycystic ovary syndrome: The expression of CNP/NPR2 was also found to be down-regulated in QUR-treated PCOS rats, inferring that QUR may affect the binding of CNP and NPR2 gene promoter-specific sequences, and regulate the transcription of CNP and NPR2 genes as well as CNP/NPR2 genes, thereby restoring ovulation and alleviating PCOS (Zheng et al., 2022b).