PGR and demyelinating disease: Nonetheless, it is unknown if progesterone also promotes the proliferation and differentiation of OPC during early oligodendrogenesis in embryonic life, as well as the PR isoform involved in progesterone effects, which is relevant in order to understand the mechanisms that underlie embryonic oligodendrogenesis, and thus develop more efficient therapies to alleviate demyelinating diseases and lesions in postnatal life.