ESR1 and breast cancer: Tumors from patients with TNBC had a higher density of TMEM doorways (p = 0.004) (Fig. 2b), macrophages (p = 0.0002) (Fig. 2c), and CSCs (nuclear SOX9high cancer cells, p = 0.0002) (Fig. 2d) than tumors from patients with ER+/HER2- breast cancer.