ESR1 and triple-negative breast carcinoma: Triple negative breast cancer (TNBC) accounts for approximately 10–15% of all cases and comprise a molecularly diverse group of tumours that lack positivity for the three major diagnostic and prognostic biomarkers clinically assessed in breast carcinomas: the estrogen receptor-α (ERα), the progesterone receptor (PR), and amplification or over-expression of the human epidermal growth factor receptor-2 (HER2) [1, 2].