Camila dos Santos’ laboratory studies the epigenetic regulation of normal and malignant mammary gland development, with an emphasis on the alterations brought by pregnancy. Significant changes mark the pre- and post-pubescence mammary developmental stages, but those associated with pregnancy have the greatest effect on cellular function, tissue reorganization, and breast cancer susceptibility. Her group has recently found that mammary glands react differently to a second pregnancy than they do to the first one, with associated changes in DNA methylation. These findings suggested that pregnancy changes the state of mammary cells, and these may permanently alter how they react to the next pregnancy. In addition, the dos Santos lab is exploring how the pregnancy-induced epigenetic changes might influence cell transformation and the risk of breast cancer. This research utilizes genomic and computational approaches to define the pre and post-pregnancy mammary epigenome. An additional objective of the dos Santos’ laboratory is to use functional genomics to discover novel transcriptional regulators that modulate mammary stem cell self-renewal, lineage specification, and cell transformation. The long-term objective of Camila’s group is to improve the notion of the mammary epigenome during normal development and use this information to gain insight into new preventive and curative strategies to target breast cancer.