RecruitingProcedureGeneration of Heart Muscle Cells From Blood or Skin Cells of Breast Cancer PatientsThe purpose of this study is to investigate whether cells from a biopsy taken from the patient skin can be transformed into cardiomyocytes the changes in cardiomyocyte (heart muscle cells) when grown in a special culture medium outside of the body. The structure and function of these cells will then be studied to determine why some patients with breast cancer who are treated with chemotherapy including anthracycline (e.g. Doxorubicin) and anti-HER2 therapy (e.g. Herceptin) develop decreased heart function.