Loss of PPARγ expression in mammary secretory epithelial cells creates a pro‐breast tumorigenic environment

Breast cancer is the leading cause of new cancer diagnoses among women. Using peroxisome proliferator‐activated receptor (PPAR)γ (+/−) mice, we showed normal expression of PPARγ was critical to stop 7,12‐dimethylbenz[a]anthracene (DMBA)‐induced breast tumorigenesis. PPARγ is expressed in many breast cell types including mammary secretory epithelial (MSE) cells. MSEs proliferate as required during pregnancy, and undergo apoptosis or reversible...