For these purposes, we used the Metastatic Breast Cancer Project (MBCProject), which has genomic (WES, n = 379 tumor samples), transcriptomic (RNA-seq, n = 200 tumor samples) and clinical data (including receptor status: 84 HR + /HER2-, 27 HR + /HER2 + , 10 HR-/HER2+, 12 HR-/HER2-), as the reference cohort28. The gene discussed is ERBB2; the disease is breast cancer.