Figure 1.

Mammary biology and cycles of remodeling requiring carefully controlled cell cycle regulation in which dysfunctional DNA repair mechanisms may instigate carcinogenesis. At any point during development and mammary remodeling, defects in repair of DNA damage can occur and become the basis for later oncogenesis. In this illustration, the relative numbers of remodeled structures (ducts and lobules) are illustrated by the mammary epithelial tree with green dots representing end buds and lobules and red dots representing lymph nodes.