Despite the recognised role of ER as a proxy for prognosis in medical decision making, it has been documented that hormone receptors such as ER are relatively weak predictors for determining outcome in patients diagnosed with breast cancer and are of limited clinical value in lymph node-negative cases (Mirza et al. 2002), which confirms that treatment guidelines based on ER alone are ill-defined. This evidence concerns the gene NR4A1 and breast carcinoma.