For the grading of breast cancer (BC), various solutions have been proposed, such as DL-based models to identify and count mitoses [39] and a CNN model for BC grading based on nuclear features [40] and tubule formation, exhibiting correlation with histologic grade and recurrence risk in early-stage estrogen receptor-positive (ER+) BC, as determined by a molecular test (Oncotype DX) [41]. This evidence concerns the gene ESR1 and breast cancer.