Despite the great efficacy shown by drugs in the clinic againstHER2 positive breast cancer, the reported resistance in patientswith long-term trastuzumab treatment must be overcome andthere is a need to identify and develop a novel therapeutic agentthat can decrease the amount of HER2 in breast cancer cellswhich at the same time will possess a molecular mechanism ofpharmacological activity that will subdue the resistancemechanisms employed against known agents. The gene discussed is ERBB2; the disease is breast carcinoma.