A C21-steroid hormone in which a pregnane skeleton carries oxo substituents at positions 3 and 20 and is unsaturated at C(4)-C(5). As a hormone, it is involved in the female menstrual cycle, pregnancy and embryogenesis of humans and other species.
Note: Use of the qualifier "multiple interactions" designates that the annotated interaction
is comprised of a complex set of reactions and/or regulatory events, possibly involving
additional chemicals and/or gene products.