Early successes in predictive biomarkers focused on single mutations, such as the BCR-ABL translocation observed in chronic lymphocytic leukemia or oncogene amplification, such as Her2-neu or EGFR. In the last half decade, therapies targeting tyrosine kinase mutations in lung cancer or high expressing immune markers in many tissue types have become standard of care. This evidence concerns the gene ERBB2 and lung carcinoma.