Abstract
Breast cancer is one of the most diagnosed cancers in women. Despite outstanding progress over the past few years, breast cancer remains the second leading cause of cancer-related death among women. This fact emphasizes the need for improved diagnostic and prognostic markers, as well as improved understanding of cancer environment, including the crosstalk between epithelial and stromal cells. The tumor microenvironment is paramount in breast cancer progression and dissemination. Accumulating evidence indicates that epigenetic phenomena such as microRNAs are extremely important in cancer homeostasis. Through the improved understanding of the molecular mechanisms involved in the microenvironment-mediated promotion of cancer growth and metastasis, novel targets for therapeutic intervention or early diagnosis may be identified.