ERBB2 and breast cancer: Breast cancer is the most common cancer (27% of all cancers) and common cause of death (16%) in around the world.1 In Asia, maximum incidence rate is in 40–50 age groups and in contrast, in western countries the increases incidence increases with age.2 The human epidermal growth factor receptor 2 (HER-2/neu) or (cerbB-2) gene is located on human chromosome 17q21 and is a member of ErbB family of receptor tyrosine kinases.3,4 Over-expression of HER-2/neu gene and its protein are associated with disease prognosis and treatment.3