ESR1 and breast cancer: The scRNASeq breast cancer data had 401 cells and originated from 6 different cell types populations: 15% estrogen receptor positive (ER+), 7% double positive (ER + HER2+), 12% BC03LN (lymph node metastasized double positive), 29% human epidermal growth factor receptor 2 positive (HER2+), 29% triple-negative breast cancer (TNBC), and 8% BC07LN (lymph node metastasized triple-negative).