Genetic data have been successfully transformed into clinical practice, for example for chronic myeloid leukemia (CML) where the application of BCR-ABL tyrosine kinase inhibitor—imatinib is widely used [34], and in case of HER2-positive breast cancer, combination of lapatynib and transtuzumab is applied for inhibition of HER2 [35]. The gene discussed is ERBB2; the disease is breast carcinoma.