Some of the reviewed biomarkers have strong prognostic potential, allowing earlier determination of disease progression (APC, RASSF1, ESR1, TMEM240), association with BC stage (GBP2, RASSF1, APC, PTEN, SMAD4), lymph node metastasis (GBP2, ESR1, PTEN) or poor differentiation grade (ESR1, RASSF1, SMAD4). The gene discussed is SMAD4; the disease is breast cancer.