Indeed, microarray-based technologies for routine prognostic screening of multigene signatures (for example, 70-gene MammaPrint for tumour aggressiveness/chemotherapy requirement/metastatic prognosis [48], Celera 14-gene for metastasis score [49], Oncotype-DX 21-gene signature for measuring risk of re-occurrence [50], and 76-gene Veridex signature for tamoxifen therapy benefit [51]) have been invaluable in supporting treatment of ER/PR positive breast cancers. Here, ESR1 is linked to neoplasm.