ESR1 and breast cancer: Some well-known biomarkers covered by STMs are BRCA1 (breast cancer 1, early onset), BRCA2 (breast cancer 2, early onset), ATM (Ataxia telangiectasia mutated), TP53 (tumor protein p53), ErbB2 (a.k.a. HER2, Human Epidermal Growth Factor Receptor 2), TFN (tumor necrosis factor) and Esr1 (Estrogen receptor 1) (for a complete list see Table 3).