The first studies for identification of variants associated with prognosis in breast cancer investigated polymorphisms of candidate genes involved in oncogenesis, such as Plasminogen activator inhibitor-1 gene [27, 28], VEGF [29], TP53 [30] or Cycline D1 genes [31] and suggested links between some gene variants and breast cancer prognosis. The gene discussed is SERPINE1; the disease is breast cancer.