There is also sizeable variation in size amongst men and women. Everlasting breast progress throughout puberty is due to estrogens along with The expansion hormone. Female humans are the one mammals that permanently acquire breasts at puberty; all other mammals build their mammary tissue in the latter period of pregnancy. https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb