There is certainly also substantial variation in sizing involving men and women. Lasting breast growth through puberty is attributable to estrogens at the side of the growth hormone. Feminine people are the one mammals that permanently establish breasts at puberty; all other mammals create their mammary tissue over the latter https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb