Key developments included implementation of phage display and yeast surface display techniques, enabling generation of diverse affibody libraries with picomolar binding affinities for critical targets including human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) which are important markers in cancer diagnostics and therapeutics [7,8,9,10,11,12,13,14]. The gene discussed is ERBB2; the disease is cancer.