Candidate prognostic biomarkers for breast cancer include elevated proliferation indices such as Ki-67 and proliferating cell nuclear antigen (PCNA); ER and PR overexpression; markers of oncogene overexpression such as c-erbB-2, TGF-a and EGFr; indicators of apoptotic imbalance including overexpression of bcl-2 and an increased bax/bcl-2 ratio; markers of disordered cell signaling such as p53 nuclear protein accumulation; alteration of differentiation signals such as overexpression of c-myc and related proteins; loss of differentiation markers such as TGF-b II receptor and retinoic acid receptor; and alteration of angiogenesis proteins such as VEGF overexpression.