Clinically, HER2 overexpression, which is observed in 10–35% of all breast cancers, has been correlated with serious prognostic breast cancer characteristics, as its amplification corresponds with tumor size, lymph node metastasis, a high S-phase fraction, aneuploidy, and a low level of steroid hormone receptors [1,2]. The gene discussed is ERBB2; the disease is breast carcinoma.