<Tr> <Td> Follicular structure </Td> <Td> Luteal structure </Td> <Td> Secretion </Td> </Tr> <Tr> <Td> Theca cells </Td> <Td> Theca lutein cells </Td> <Td> androgens, progesterone </Td> </Tr> <Tr> <Td> Granulosa cells </Td> <Td> Granulosa lutein cells </Td> <Td> progesterone, estrogen (majority), and inhibin A </Td> </Tr> <P> Like the previous theca cells, the theca lutein cells lack the aromatase enzyme that is necessary to produce estrogen, so they can only perform steroidogenesis until formation of androgens . The granulosa lutein cells do have aromatase, and use it to produce estrogens, using the androgens previously synthesized by the theca lutein cells, as the granulosa lutein cells in themselves do not have the 17α - hydroxylase or 17, 20 lyase to produce androgens . Once the corpus luteum regresses the remnant is known as corpus albicans . </P>

Which hormone is responsible for the formation of the corpus luteum