Figure 1
Control of mammary gland lobuloalveolar growth. Hormones from the pituitary gland, placenta, and ovaries converge on mammary epithelial cells that express receptors for estrogen, progesterone (esp. PR-B), and PRL. Activation of receptor-positive cells induces two mediators, IGF2, which acts as a diffusible autocrine–paracrine mitogen, and RANKL, which acts as a juxtacrine mitogen for neighboring cells. The Zn-finger transcription factor GATA3 is permissive for lobuloalveolar growth by inducing IKKα.
