Ruth Dannenfelser will present her MSE thesis talk on Thursday April 24 at 3PM in room 301 (note room!). The members of her committee are Olga Troyanskaya, advisor and Kai Li, reader. Everyone is invited to attend her talk. Her abstract follows below. ----- Original Message ----- The immune system is a complex set of biological processes and structures that work together to protect the human body. A main component of this system are the lymphocytes, white blood cells, which are responsible for identifying and destroying invading cells, including tumors. In breast cancer it has been shown that the level of the immune infiltrate in the tumors is one of the key determinants of prognosis and survival. However, a more detailed view of the relative abundances of specific lymphocytes in these tumors and their functional role in breast cancer remains largely unexplored. Here we attempt to quantify the level of immune activity in patient tumors by examining the expression of four specific lymphocytes: B cells, cytotoxic T, T helper 1, and T helper 2 cells. We utilize a machine learning approach, in silico nano-dissection, to expand small lists of immune specific markers into larger cell type specific signatures. We then use these signatures to profile breast tumors across different clinical groupings revealing consistent variations in lymphocyte expression across subtypes, morphologies, and treatments.