Dr. Abdel-Hafiz joined the division faculty in 2003, and is currently an Assistant Professor. Breast cancer is the second leading cause of cancer-related deaths among American women. Breast malignancies affect approximately 1 in 10 women over their lifetime. Dr. Abdel-Hafiz's research focuses on the female sex steroid hormones estradiol and progesterone, and their cognate receptors, ER and PR. In particular, his group is interested in how SUMOylation, a widespread posttranslational modification, affects ER and PR, and their role in breast cancer. His research aims to understand the molecular mechanism(s) by which SUMOylation of PR and/or steroid hormone receptor cofactors affect estrogen-dependent tumor growth. Current projects are examining how SUMOylation affects ER- and PR- regulated gene expression using human breast cancer cell models with normal or altered SUMOylation activity. A second project investigates how SUMOylation affects the ability of estradiol and tamoxifen to regulate breast tumor growth.