Mammary gland gestation, serum progesterone remains at a stably high concentration so signaling through its receptor is continuously activated. As one of the transcribed genes, Wnts secreted from mammary epithelial cells act paracrinely to induce more neighboring cells' branching. When the lactiferous duct tree is almost ready, "leaves" alveoli are differentiated from luminal epithelial cells and added at the end of each branch. In late pregnancy and for the first few days after giving birth, colostrum is secreted. Milk secretion (lactation) begins a few days later due to reduction in circulating progesterone and the presence of another important hormone prolactin, which mediates
Aka II of Commagene the astrologer and became the personal friend of the Roman emperor Tiberius, who reigned from 14 until 37. As Tiberius had held Thrasyllus in the highest honor, Tiberius rewarded Thrasyllus for his friendship by giving him, Roman citizenship to him and his family. From given Roman citizenship, Aka II became known as "Claudia Aka", as her husband became known as "Tiberius Claudius Thrasyllus". Aka II died at an unknown date in the first century. Aka II bore Thrasyllus two known children: Aka II of Commagene Aka II of Commagene also known as Aka II or Aka () was a Princess