ESR1 and breast cancer: Lastly, we divided our study population into different subgroups based on TMN stage (TMN1, TMN2, and TMN3), tumor size (T ≤ 2 cm and T ≥ 2 cm), lymph node ( ±), histologic grade (grade 2 and grade 3), histologic type (invasive ductal and other types), ER (ER + /ER−), PR (PR + /PR−), and HER2 (HER2 + /HER2−), and then analyzed the impact of SCUBE3 expression on prognosis of breast cancer patients in each subgroup.