The ESCAT (Esmo Scale For Clinical Actionability Of Molecular Targets) has identified the most common molecular alterations associated with breast cancer treatment effectiveness using targetable therapy, including “ERBB2 amplification, germline BRCA1/2 mutations, PI3KCA mutations, microsatellite instability (MSI), and NTRK translocations”. The gene discussed is ERBB2; the disease is breast cancer.