Abstract
Lactation defines the ability of mammals to feed their young. The mammary gland fully develops during pregnancy and is at its most productive during lactation [ 1, 2]. Milk production and secretion are vital for nutrition and survival of neonatal mammals. Despite the obvious importance of lactation, the local mechanisms regulating the onset of lactation are not well understood. During pregnancy hormonal stimulation, mostly through estrogen, progesterone, and prolactin, drives formation of lobulo-alveolar structures, the milk producing unit of the mammary gland [ 1, 3]. In murine mammary glands, lobulo-alveolar structures develop during pregnancy.