ESR1 and neoplasm: CD90 “high” positivity patients did not significantly differ from CD90 “low” positivity patients for all evaluated characteristics, namely: age at diagnosis (p = 0.119), tumor size (p = 0.959), Perou/Solie classification (p = 0.638), lymph node status (p = 0.859), histological grade (0.411), adjuvant therapy (p = 0.538), ER (p = 0.738), PR (p = 0.557), and HER2 (p = 0.717) status.