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
What U See Is What U Get What U See Is What U Get "What U See Is What U Get" is the first single from Xzibit's second album, "40 Dayz & 40 Nightz". In its first week the song peaked at #50 on the "Billboard" Hot 100, being Xzibit's highest charting single. It peaked at #3 on Hot Rap Singles, his highest on that chart. A music video directed by Gregory Dark was filmed in Los Angeles. The deceptively simplistic premise of the video is Xzibit's trek to a nearby shop after being asked to pick up some milk. On his way, Xzibit greets several friends,